The field research will take Joan and Paul about five months; it will be a long time _____ we meet them again.

Don‵t _____to put on your raincoat when you go out . It‵s rainy now.—OK，Mom .

―More than fifty students competed ________ each other in the composition competition.―But they could only compete________three medals.

It is possible that ______ 2030, cars and airplanes will run on the new fuel

He _____ cards with his friends, but now he _____ a walk after supper.