1、Unit 7 You mustnt drop litter in the park.,You mustnt,pick flowers,in the garden.,paint,You mustnt,on the wall.,Harvard university,shout,You mustnt,in the library.,sit,You mustnt,on the grass.,throw food at animals.,You mustnt,drive,You mustnt,here,fish,You mustnt,in the lake.,You mustnt drop litter
2、 in the park.pick flowers in the garden.shout in the library.fish in the lake.drive here.paint on the wall.sit on the grass.throw food at animals.情态动词后接动词原型，常见的情态动词有 can/could should must may/might shall,There is an apple on the tree.,There are two apples on the tree.,There are three apples on the t
3、ree.,There be 有 There is +可数名词单数 / 不可数名词 There are + 可数名词复数,There are some ducks in the water.,There are some people in the boat.,There are some fish in the water.,There are some children on the grass.,There are some boats in the water.,There are some kites in the sky.,There is a hippo in the water.,There is a swimming pool in the park.,There is a playground in the park.,There is a river in the park.,There is a bird flying in the sky.,There are two birds flying in the sky.,There is/are ing.,
