想一想，选一选。

1. 当你觉得书包太重时，你应说：[ ]

A. My schoolbag is too heavy.

B. This is my schoolbag.

2. 当你想对帮助你的人表达感激之情时，你应说：[ ]

A. You're welcome.

B. Thank you so much.

3. 晚饭后，你想告诉妈妈你吃饱了，你应说： [ ]

A. I am full.

B. I am tired.

He traveled to many mountain villages and saw many poor children out of school. This experience _______ his life.

A．would change

B．had changed

C．was to change

D．was changing