下列物质在空气中敞口放置一段时间后，因发生化学变化而使质量增加的是（  ）

    It's Sunday morning. There are many people in the park, some boys are playing basketball. There are some girls under a big tree. They're singing and dancing. What are those women doing? They are drinking tea. Look at the woman in a blue coat. Who's she? She's my mother. She is talking to Edward. Edward is her student. He is a good student. He studies hard. He's good at all the subjects. And he's friendly to all his teachers and his friends.

甘地领导的非暴力不合作运动也包含了经济方面的斗争，他提倡的经济自主运动的主要内容是(　　)

下列有关利用“生物反应器”进行生产的叙述，错误的是（　　）

读《渡江战役》图，完成下列问题。