_______ from the moon, our earth, with water _______seventy percent of its surface, appears a blue ball
| A．Seen; covered | B．Seeing; covering |
| C．Seen; covering | D．Seeing; covered |
Only then ______ how much damage had been caused.
| A．had she realized | B．she realized | C．did she realize | D．she had realized |
—How long will you be staying?
—I don't know.______ .
| A．That's OK | B．Never mind |
| C．It depends | D．It doesn't matter |
The ______ on his face told me that he was angry.
| A．impression | B．sight | C．appearance | D．expression |
_____ we stood at the top of the building，we were able to enjoy the town below clearly.
| A．As | B．Although | C．Unless | D．Until |
After he ______ the table，he sat down on the sofa for a rest，waiting for his guests.
| A．lay | B．laid | C．put | D．made |