求解一道专四题bythetime,Normanhaddecidedthathewantedtobeanartista,inhisearlyteensb,hewasinhisearlyteens这里为什么选b呢?我觉得后面已经有主语了,感觉好像是有独立主格句子

Question

求解一道专四题
by the time ___ ,Norman had decided that he wanted to be an artist
a,in his early teens b,he was in his early teens
这里为什么选b呢?我觉得后面已经有主语了,感觉好像是有独立主格句子

Answer 1

by the time 到…的时候,后面要接句子,不能接介词短语.
比如：
By the time the earthquake ended,millions of people became homeless.
到地震结束的时候,很多人变得无家可归.