Riding on the swings and playing with the ducks in the pond _____ our children’s greatest pleasures when we took them to the park.

Every student as well as teachers who ____ to visit the museum_____ asked to be at the school gate on time.

Three-fourths of the surface of the earth＿＿＿sea．

Internet, as well as the telephones, ________ an important part in our daily life.

----- What does Canada export?---- A large quantity of wheat_____ sent away.