China is going to         a manned space station around 2020 to explore more space.

A, set up         B. put up     

C. wake up        D. turn up

能引起硅沉着病的粉尘是()

A．石棉尘 

B．二氧化硅尘 

C．铁矿尘 

D．铝尘 

E．水泥尘