By the time hefourteen years old, headvanced mathematics all by hims

游客2024-06-20 8

问题 By the time he______fourteen years old, he______advanced mathematics all by himself.

选项 A、has been: learned
B、had been: had learned
C、was: learned
D、was: had learned

答案 D

解析本题考查动词的时态。“by+过去时间”是过去完成时的时态标志，因此本句主句部分谓语动词用过去完成时，而从句部分谓语动词用一般过去时。D为正确选项。

转载请注明原文地址:https://tihaiku.com/zcyy/3642173.html

相关试题推荐

随机试题

最新回复(0)

By the time he______fourteen years old, he______advanced mathematics all by hims