出现在《中国国家形象》宣传片中，被西方称为“中国第五大发明”的是什么？
参考答案：
超级杂交水稻
若数据的分布比较均匀，应编制（）。
A.异距数列
B.等距数列
C.单项式数列
D.组距式数列
用所给词的适当形式填空。
1. —When _____ you _____ ( start) skating?
—At nine o'clock.
2. Jack Chen _____ ( work) as an actor for over thirty years.
3. —I _____ ( see) the film Chicken, Run.
—When and where _____ you _____ (see) it?
—Sorry, I can't remember.
4. More than 15 years has passed since I _____ ( become ) a teacher.
5. My hobby is _____ (collect) all kinds of coins.
