Protecting the earth is not ____ to be left to the government．Everybody should be concerned．
| A．nothing | B．something | C．everything | D．anything |
—People often don't appreciate what they have, do they?
—No, _____ they lose it.
| A．if | B．after | C．when | D．until |
—Did Ann fail in English?
—She ____. Don't you notice that she looks depressed?
| A．might | B．must | C．may have | D．could have |
People believe that the China Dream is not very difficult ____ so long as the whole nation works hard for it.
| A．realizing | B．to be realized | C．realized | D．to realize |
Try not to cough more than you can_____since it may cause problems to your lungs.
| A．help | B．allow | C．stop | D．check |
Color shapes our view of __world and it may have ___far more influence on our lives than many of us realize.
| A．a; a | B．the; / | C．the; the | D．the; a |