(The metal) aluminum (has been) (first) isolated (early) in the nineteenth centu

游客2025-03-16 16

问题 (The metal) aluminum (has been) (first) isolated (early) in the nineteenth century.

选项 A、The metal
B、has been
C、first
D、early

答案 B

解析应改为was。本句中有具体表示过去的时间状语，所以应该用一般过去时。

转载请注明原文地址:https://tihaiku.com/zcyy/3999584.html

相关试题推荐

随机试题

最新回复(0)

Theagriculturalrevolutioninthenineteenthcenturyinvolvedtwothings:t