问题

Up to now, our society ________ with limited living space and a shortage of natural resources.

A:has been challenged
B:is being challenged
C:is challenging
D:has challenged

正确答案是：

同类题型

he had worked hard all the time, hefailed the exam again

We would appreciate it if customers don’t______ toleave their suggestions and expectations for our product.

the front door ___ ,he had to enter the room through the back door.

160. It seemed that there was strange sound outside. We ________ carefully but_____nothing.

It’s certainly been a long time _________ we met last time