People cut down too many trees, _____ the greenhouse effect becomes more and more serious.

People cut down too many trees, _____ the greenhouse effect becomes more and more serious.

#56516

because

although

推荐题目

Remember to wash your hands __________ you have meals.

#56692

before

until

though

unless

—Do you like playing tennis? —No， ____ I like sports．I play football every Sunday

#58527

and

but

I work harder at my lessons this year _____ I have made good progress.

#55988

but

and

for

 As we all know the H1N1 Flu is so serious, students can’t go into the school _______ they take the temperature and get sure they don’t have a fever.

#55588

till

after

when

until

 I want to know          Tom can help me with my maths.

#56581

because

although

共1556题