用括号中所给动词的适当形式填空

1. Don't spend too much time __________(chat) on the Internet.

2. We always have a great time __________(study) English.

3. Our teacher asked us __________(open) the windows.

4. What games __________ they __________(play)? Let's go and have a look.

5. Simon __________(go) to the club last night.

光合作用被称为地球上最伟大的化学反应，它是给地球生物生产了富含能量的有机物和氧气。光合作用可表示为：二氧化碳 + 水  淀粉 + 氧气。根据以上信息判断，下列有关淀粉的说法中不正确的是

A．肯定含有碳元素

B．肯定含有氢元素

C．肯定含有碳、氢二种元素

D．肯定含有碳、氢、氧三种元素