(2019唐山市路南区二模) This is a ________ matter. Don't joke about it.
A.serious B.difficult C.proper D.relaxing
(2019 石家庄裕华区一模) I didn't hear someone knocking at the door. I ________ to my friend on the phone at that time.
A.talk B.talked C.is talking D.was talking
(2019 石家庄市一模) It's ________ to divide the waste into different kinds before we get rid of it.
A.necessary B.possible C.interesting D.humorous
noise pollution, and we can live in a quiet environment.
A. Prevent B. Preventing C. Prevented D. To prevent
(2019 无锡改编) You haven't said a ________ word since last Friday. What's wrong?
A.simple B.single C.similar D.silent
(2019天津改编) You ________ walk on the wet hill path because you might fall and hurt yourself.
A.must B.mustn't C.needn't D.need
