戴爾美語練功坊 托福閱讀實力測驗題5/10 - 英檢

戴爾美語練功坊…托福閱讀實力測驗試題(5/10日)

Lightning

Lightning is a brilliant flash of light produced by an electrical
discharge from a storm cloud. The electrical discharge takes
place when the attractive tension between a region of negatively
charged particles and a region of positively charged particles
becomes so great that the charged particles suddenly rush
together. The coming together of the oppositely charged particles
neutralizes the electrical tension and releases a tremendous amount
of energy, which we see as lightning. The separation of positively
and negatively charged particles takes place during the development
of the storm cloud.

The separation of charged particles that forms in a storm cloud has a
sandwich-like structure. Concentration of positively charged particles
develops at the top and bottom of the cloud, but the middle region
becomes negatively charged. Recent measurements made in the field
together with laboratory simulations offer a promising explanation of
how this structure of charged particles forms. What happens is that
small (millimeter-to centimeter-size) pellets of ice form in the cold
upper regions of the cloud. When these ice pellets fall, some of them
strike much smaller ice crystals in the center of the cloud. The
temperature at the center of the cloud is about -15℃ or lower. At
such temperature, the collision between the ice pellets and the ice
crystals causes electrical charges to shift so that the ice pellets acquire
a negative charge and the ice crystals become positively charged.
Then updraft wind currents carry the light, positively charged ice
crystals up to the top of the cloud. The heavier, negatively charged ice
pellets are left to concentrate in the center. This process explains why
the top of the cloud becomes positively charged, while the center
becomes negatively charged. The negatively charged region is large:
several hundred meters thick and several kilometers in diameter.
Below this large, cold, negatively charged region, the cloud is warmer
than -15℃, and at these temperatures, collision between ice crystal
and falling ice pellets produce positively charged ice pellets that then
populate a small region at the base of the cloud.

Most lightning takes place within a cloud when the charge separation
within the cloud collapses. However, as the storm cloud develops, the
ground beneath the cloud becomes positively charged and lightning
can take place in the form of an electrical discharge between the
negative charge of the cloud and the positively charged ground.
Lightning that strikes the ground is the most likely to be destructive,
so even though it represents only 20 percent of all lightning, it has
received a lot of scientific attention.

Using high-speed photograph, scientists have determined that there
are two steps to the occurrence of lightning from a cloud to the
ground. First, a channel, or path, is formed that connects the cloud
and the ground. Then a strong current of electrons follows that path
from the cloud to the ground, and it is that current that illuminates the
channel as the lightning we see.

The formation of the channel is initiated when electrons surge from
the cloud base toward the ground. When a stream of these negatively
charged electrons comes within 100 meters of the ground, it is met by
a stream of positively charged particles that comes up from the
ground. When the negatively and positively charged streams meet, a
complete channel connecting the cloud and the ground is formed.
The channel is only a few centimeters in diameter, but that is wide
enough for electrons to follow the channel to the ground in the visible
form of a flash of lightning. The stream of positive particles that meets
the surge of electron from the cloud often arises from a tall, pointed
structure such as a metal flagpole or a tower. That is why the
subsequent lightning that follows the completed channel often strikes
a tall structure. (A)■ Once a channel has been formed, it is usually used
by several lightning discharges, each of them consisting of a stream of
electrons from the cloud meeting a stream of positive particles along
the established path. (B)■ Sometimes, however, a stream of electrons
following an established channel is met by a positive stream making a
new path up from the ground. (C)■ The result is forked lightning that
strikes the ground in two places. (D)■

1. According to paragraph 1, all of the following take place in the
development of a flash of lightning EXCEPT
(A) great tension between two oppositely charged regions
(B) an increase in negatively charged particles over positively charged
particles
(C) oppositely charged particles coming together
(D) the release of electrical energy in the form of visible light

2. The word " tremendous " in the passage is closest in meaning to
(A) distinct
(B) discerning
(C) huge
(D) immediate

3. According to paragraph 2, what causes ice crystals to become
positively charged?
(A) Collisions with ice pellets
(B) Collisions with negatively charged ice crystals at the base of cloud
(C) Becoming concentrated in the central region of the cloud
(D) Forming at a temperature greater than -15℃

4. The word " acquire " in the passage is closest in meaning to
(A) reject
(B) obtain
(C) implore
(D) ensue

5. According to paragraph 2, why are positively charged ice pellets
produced in the lower part of the cloud?
(A) Collisions between ice crystals and ice pellets increase in number
in the lower part of the cloud.
(B) The lower part of the cloud is smaller than the region above it.
(C) More ice pellets than ice crystals reach the lower part of the cloud.
(D) Temperature in the lower part of the cloud are warmer than -15℃.

6. It can be inferred from the paragraph 2 that part of the reason that
the top of a storm cloud becomes positively charged is that
(A) the top of the cloud is warmer than the middle of the cloud
(B) the middle of the cloud is already occupied by positively charged
particles
(C) the negatively charged ice pellets are too heavy to be carried by
the updrafts that move ice crystals
(D) collisions between ice pellets in the top of the cloud produce
mainly positively charged particles

7. The author remarks that "Lightning that strikes the ground is the
most likely to be destructive" in order to explain why
(A) this form of lightning has been investigated so much
(B) this form of lightning is not as common as lightning within a cloud
(C) scientific understanding of this form of lightning is important
(D) the buildup of positive charge on the ground beneath a storm
cloud can have serious consequences

8. Which of the following claims about lightning strikes can be
inferred from paragraph 5?
(A) During a lightning strike the diameter of the channel the electrons
follow is considerably enlarged beyond a few centimeters.
(B) A building is unlikely to be hit by lightning unless it is at least 100
meters tall.
(C) A building is hit by a lightning strike because the building itself has
first determined the path the lightning then takes to it.
(D) The light of a lightning strike first appears at the point where the
streams of negative and positive particles meet.

Answers:
1. 根據題幹-- According to paragraph 1, all of the following take place
in the development of a flash of lightning EXCEPT
原文定位第一段:
Lightning is a brilliant flash of light produced by an electrical discharge
from a storm cloud. The electrical discharge takes place when the
attractive tension between a region of negatively charged particles
and a region of positively charged particles becomes so great that the
charged particles suddenly rush together. The coming together of the
oppositely charged particles neutralizes the electrical tension and
releases a tremendous amount of energy, which we see as lightning.
The separation of positively and negatively charged particles takes
place during the development of the storm cloud.
答案為: B

2. tremendous 巨大的
(A) distinct 清楚的 (B) discerning 敏銳的 (C) huge 巨大的
(D) immediate 立即的
答案為: C

3. According to paragraph 2, what causes ice crystals to become
positively charged?
此考題為事實細節訊息題 (Factual Detail Information)
原文定位第二段: Key words --- ice crystal / positively charged
The temperature at the center of the cloud is about -15℃ or lower. At
such temperature, the collision between the ice pellets and the ice
crystals causes electrical charges to shift so that the ice pellets acquire
a negative charge and the ice crystals become positively charged.
答案為: A

4. acquire 獲得/ 取得
--- (A) reject 拒絕 (B) obtain 獲得 (C) implore 懇求 (D) ensue 後續
答案為: B

5. According to paragraph 2, why are positively charged ice pellets
produced in the lower part of the cloud?

Key words : ice pellets / lower part of the cloud
原文定位第二段:
Below this large, cold, negatively charged region, the cloud is warmer
than -15℃, and at these temperatures, collision between ice crystal
and falling ice pellets produce positively charged ice pellets that then
populate a small region at the base of the cloud.
答案為: D

6. It can be inferred from the paragraph 2 that part of the reason that
the top of a storm cloud becomes positively charged is that
此題主要測驗inference (推論) --- 技巧為搜尋(1) 轉折語; (2) 極致詞 ;
(3) 強調字詞.

At such temperature, the collision between the ice pellets and the ice
crystals causes electrical charges to shift so that the ice pellets acquire
a negative charge and the ice crystals become positively charged.
Then updraft wind currents carry the light, positively charged ice
crystals up to the top of the cloud.
題意 --- 暴風雲之頂端變為正電荷原因可推論出?
原文敘述為 " 上升之氣流風較輕正電荷粒子吹向雲端上. 進而推論較重之負電荷即仍存在其雲之中心區域.
答案為 C .

7. The author remarks that "Lightning that strikes the ground is the
most likely to be destructive" in order to explain why
此題測驗 修辭目的 ( Rhetorical Purpose) ---
將Testing words --- Lightning that strikes the ground is the most
likely to be destructive --- 回溯原文;
Lightning that strikes the ground is the most likely to be destructive,
so even though it represents only 20 percent of all lightning, it has
received a lot of scientific attention.
答案為: A

8. Which of the following claims about lightning strikes can be inferred
from paragraph 5?
此題主要測驗inference (推論) ---
技巧為搜尋(1) 轉折語; (2) 極致詞 ; (3) 強調字詞.
When the negatively and positively charged streams meet, a complete
channel connecting the cloud and the ground is formed. The channel
is only a few centimeters in diameter, but that is wide enough for
electrons to follow the channel to the ground in the visible form of a
flash of lightning. The stream of positive particles that meets the surge
of electron from the cloud often arises from a tall, pointed structure
such as a metal flagpole or a tower. That is why the subsequent
lightning that follows the completed channel often strikes a tall
structure.
答案為: C



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