---Do you know about a very popular toy--- the yo-yo(悠悠球)?---Yes. Filipinos(菲律宾人) invented it ________ accident. And it ________ helping kill animals.
Mr Smith is friendly___us ,But he is very strict_____our studies.
You’d better get your clothes____for they’re so dirty.
The girl looked____at the good news.
Chinese___by more and more people in the world now.
We will have a ___holiday after the exam.