选择恰当的选项填空 there is,there are,there aren't,there wasn't,there were,there weren't
(急!)
1、________a lot of boats fifty years ago.
2、now__________many people and cars here.
3、30 years ago,_________a lot of people,factories or a subway here.
4、50 years ago,_________a tunnel,a highway or a subway.
5、_________a bridge on the river now