护理依赖指伤、病致残疾者因生活不能自理需依赖他人护理者，生活自理范围主要包括以下（）项：

A、进食

B、翻身

C、大小便

D、穿衣洗漱

E、自我移动

F、上楼梯

The air in big cities _____very dirty by factories.

A．are often made

B．is often made

C．have often made

D．has often made