By the middle of the 21st century, the vast majority of the world’s population will be living in the cities ______ in the country.

“It is not only you but also Tom who________, ” said the teacher after knowing what had happened.[ ]

Hurry up, kids! The school bus is coming. We have time left.

u have any doubts about your health, you’d better______ your doctor at once.

下列句中加点虚词意思和用法相同的一项（ ）