（）年中国出现了煤炭消费量的下降，二氧化碳排放量下降0.7%。
A.2014
B.2012
C.2013
D.2010
参考答案：A
用所给动词的正确形式填空。
1. The boy ( draw ) a picture now.
2. Listen! Some girls ( sing ) in the classroom.
3. My mother ( cook ) some nice food now.
4. What you ( do ) now?
5. Look! They ( have ) an English lesson.
6. They ( not water ) the flowers now.
7. Look! The girls ( dance ) in the classroom.
8. What is our granddaughter doing?
She ( listen ) to music.
9. It's 5 o'clock now. We ( have ) supper now.
10. Helen ( wash ) clothes?
Yes, she is.
足球以1.0m/s的速度水平飞向墙壁，碰到墙壁经0.1s后以1.0m/s的速度沿同一直线反弹回来，足球在与墙壁碰撞过程中（）
A.平均加速度的大小为2m/s2
B.平均加速度的大小为20m/s2
C.平均加速度的大小为零
D.足球碰壁前后速度相同，速度没有变化
