Some methods to prevent soil erosion are ploughing parallel with the slopes of hills, to plant trees on unproductive land, and rotating crops.
A.some
B.to prevent
C.are
D.to plant

In public places, you should ask everyone for permission before you ________a cigarette.
A.put out
B.put up
C.turn up
D.light up

More people speak English than any other language, but non-native speakers now_____ native speakers by three to one.
A.outnumber
B.overtake
C.pass
D.dominate

"What was your impression of last night‘s movie?” “ _____speaking, I thought it was rather boring."
A.Very
B.Really
C.Honest
D.Honestly

A.validity
B.tremendous
C.flexible
D.commercial

I find myself at a loss to understand Harold’s behavior.
A.I lost contact with Harold. so l couldn’t understand his behavior.
B.I find Harold's behavior quite incomprehensible.
C.I understand Harold‘s behavior completely.
D.I have to lose a lot to understand Harold‘s behavior.

American Online is an unusual digital company because_____
A.it used to make video games
B.it is innovative
C.it makes money
D.it has joined with another company

Certain species of penicillin are used  to ripe cheese.
A.Certain
B.of
C.are used
D.to ripe

Anita works really hard and ___________ to be paid more.
A.worth
B.values 
C.deserves
D.requires

I hope our plane will leave on __________  .
A.hour 
B.schedule 
C.plan 
D.timetable