精品一区二区免费在线观看_国产精品久久久久久av福利软件_97成人精品区在线播放_国内成人精品一区

1. I got the pen on my ________ (twelve) birthday.
2. Parents should teach their children to make decisions by ________ (they).
3. There are many little ________ (collect) in our class.
4. He was so tired that he fell fast _________ (sleep).
5. We must be careful when we _________ (across) the road.

[     ]

A. it
B. one
C. this
D. that