. — Why does the Lake smell terrible?
—Because large quantities of water______.
| A．has polluted | B．have been polluted |
| C．has been polluted | D．is being polluted |
----Why didn’t you come to meet me, Bill?
----Sorry, dear. But I really forgot where I was _____ to meet you.
| A．demanded | B．supposed |
| C．delighted | D．Squeezed |
_______from the moon, our earth, with water _____about 70 percent of its surface, appears like a blue ball.
| A．Seen; covered | B．Seeing; covering |
| C．Seen; covering | D．Seeing; covered |
---Have you got any particular plans for the coming holiday?
---Yes. __________, I’m going to visit some homes for the old in the city.
| A．If ever | B．If busy | C．If so | D．If possible |
---Have the arrangements for the concert next Saturday been all _______?
---Not yet. We haven’t found a free hand.
| A．in store | B．in trouble | C．in turn | D．in place |
___________in the mountain for a week, the students were finally saved by the local police .
| A．Having lost | B．Lost | C．Being lost | D．Losing |