er why the thinnest plastics bags, though ________ , are still in use here.—Well,it’s no easy job to solve this problem effectively.

You’re thirsty(口渴). ____ have a glass of milk—Good idea.

Lucy is ill.She has abad cold for several days.

Look at the machine in the corner. I haven’t seen it before.—It ________ examining the patient.

There isn’t _________________ at the meeting.—I think so.