2. 写出下列句子中重读的虚词。
①We saw him playing by the river. (by)
②On my way to school, my bike was broken. (On)
③I ’m sorry I can ’t do that. (can ’t)
④Didn ’t I tell you yesterday? (Didn ’t)
⑤—Are you a student? —Yes, I am. (am)
3. 试比较以下两句中boys是否重读。
—How many boys are there in the room?
—There are twenty boys in it.