I have to go to the new building under_____ construction, and can you give me _____ lift?

A．a, a

B．a,/

C．/, a

D．/,/

原油的危险特性是（）。

A、易流动、易蒸发、易爆炸

B、易蒸发、易燃烧、易爆炸

C、易冻凝、易燃烧、易蒸发

D、易流动、易冻凝、易爆炸