A：①②
B：①③
C：②④
D：③④
— I think that this is an interesting lecture _____.
— Oh, come on! No lectures for me. I've been tired ____ to lectures.
张学良、杨虎城发动“双十二事变”的主要目的是（ ）
“鸠占鹊巢”说明“鸠”在生殖和发育过程中没有经历的阶段是（ ）
