Trial and error are the source of our knowledge.A、isB、wereC、hasD、have beenA时

游客2025-01-21 38

问题 Trial and error are the source of our knowledge.

选项 A、is
B、were
C、has
D、have been

答案 A

解析时态应用。短语trial and error(反复实验)是单数主语，后面谓语动词应用第三人称单数的“is”而非“are”。

转载请注明原文地址:https://tihaiku.com/zcyy/3922792.html

相关试题推荐

随机试题

最新回复(0)