When ______ you come here We ______ here last week.

I thewonderful World Cup finD．need have watched

If you are a distance learner,it is a good idea to set yourself a ________learning goal for each day or each week. [ ]

Pollution is a serious problem. Scientists will _______ some good ways to save it.

blictransportation in this city is very convenient, where many buses run ______.