TPO17 Europe's Early Sea Trade with Asia - 英檢

請問第九題

Why does the author include the information that Western Europeans had
[developed and put into use the magnetic compass]

1. To provide an example of an instrument that was developed after caravels had
begun traveling across oceans

2. To provide an example of an improvement that resulted directly from the
invention of the astrolabe

3. To identify one of the technological advances that made sea trade with the
East possible

4. To explain how the problem of determining longitude was solved

正確答案是3 但我選2而且想不出來為什麼2不行 > <

因為文章前面有提到magnetic compass就算在雲遮住太陽和星星時也可以定位

且有說到astrolable是用計算太陽星星高度和夾角來定位觀測者所在的緯度

所以我感覺compass好像是要補足astrolable之不足而發明出來的...> <

麻煩各位神人幫我解答一下

謝謝!!(鞠躬)

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