23．She has been ________ over his strange letter for several weeks, but she still figures out nothing about it.
A．puzzling B．worried
C．troubled D．anxious
答案与解析：A 句意：她对他那封奇怪的信苦苦思索了好几周，可还是没弄明白。puzzle over...意为“对……苦苦思索”。
24．—Were you told to attend the meeting? I didn't see you anyway.
—________， but I had an accident on the way.
A．I was going B．I would
C．I should have D．I'd like to
答案与解析：C 根据上下文可知，“我本该去，但路上出了事，所以没有去”。should have done表示“本该做而没有做”。如果A项改为I was going to也是正确的。
