This factory produced much dirty water, which resulted in a wide______of environmental problems．
A．branchB．range
C．speciesD．wave
Please tell me how the accident _______．I am still in the dark．
A．came upB．came out
C．came toD．came about
It is______ of him to set his aim high but do little, so he is always leaving things undone．
A．specificB．typical
C．flexibleD．widespread
— Do you think it's a good idea to make friends with your students？
—________, I do．I think it's a great idea．
A．ReallyB．Hopefully
C．ActuallyD．Eventually
Mary couldn’t________ the terrible working conditions in that factory and resigned last week．
A．catch up withB．keep up with
C．put up withD．come up with
Some passers-by witnessed the car accident ______ five passengers were killed, a baby included．
A．whereB．whichC．thatD．when
