一、 单项填空（本题共10小题；每小题1分，满分10分）
从A、B、C、D四个选项中，选入可以填入空白处的最佳答案。
1.---Who’s that boy?
---Liang Bo. He is___ very popular singer in Voice of China.
A. the B. an C. a D. /
2. ---My brother is a basketball player.
---And he usually_____ very hard on the playground.
A has practiced B is practicing C practices D practiced
3. _____should not be allowed to go out at night.
A. Twelve-year-old B. Twelve-year-olds C. Twelve year old D. Twelve years old
