1 . At the Chinese art festival, there are different stands ________ artists demonstrate their skills and teach the visitors.

A．where

B．which

C．that

D．when

2 . We all need to get involved in saving energy ________ it's at work, at home, or at school.

A．unless

B．once

C．whether

D．because

3 . What puzzles Lily's friends is ________ she always has so many crazy ideas.

A．whether

B．why

C．what

D．when

4 . Currently, about 35,000 works ________ in over 300 rooms in the Louvre, and it would take a lifetime to see everything.

A．were displaying	B．are displaying
C．were being displayed	D．are being displayed

5 . William Hastie once suggested that history informs us of past mistakes ________ we can learn without repeating them.

A．from which

B．in which

C．with whom

D．for whom

6 . We ________ quite enough work for the morning; now let's take a break.

A．have done

B．will do

C．had done

D．were doing

8 . While rock-climbing, you need to remain very ________ so that you won't make any dangerous errors.

A．satisfied

B．focused

C．amused

D．delighted

9 . Great improvements in public health have been brought about by ________ in medical science.

A．traditions

B．advances

C．pressures

D．examples

10 . China's National Highway 318, ________ over 5,000 kilometers from Shanghai to Zhangmu, Tibet, is known as the "heavenly road“ for its amazing views.

A．to extend

B．extended

C．extending

D．being extended