2002年5月1日起，中国对强制性产品认证使用的标志为______。

A．“长城”标志

B．“CCIB”标志

C．“CCC”标志

D．方圆认证标志

根据汉语提示写单词。

1．How many _________ (国家) are there in the world?

2．This is the _________ (开始) of our tour.

3．Children should _________ (睡觉) for more than eight hours every day.

4．The girl is _________ (从未) late for school.

5．I think Beijing Duck is very _________ (美味的).