I happened to have read a book or two by the famous writer,when tom_I happened to have read a book or two by the famous writer,_ Tom invited me to go with him to the lecture,I gladly acceptedAwhen whenBif so Csince when Dsince though选C为什么
问题描述：
I happened to have read a book or two by the famous writer,when tom
_I happened to have read a book or two by the famous writer,_ Tom invited me to go with him to the lecture,I gladly accepted
Awhen whenBif so Csince when Dsince though
选C为什么
答
先读明白啥意思：
汤姆邀请我和他一起去参加一个演讲的时候,我刚好看过一到二本关于那位著名作家的书.所以我很高兴得答应了.
since 当因为,既然讲
而其他选项语义不通