7．Perhaps it will never be known __________ he did with those materials on the incident．
| A．that | B．what | C．which | D．how |
In English class, our teacher often creates an environment _____ we are given the opportunity to solve problems ourselves.
| A．when | B．where | C．which | D．that |
“match between these two teams was exciting," said Federer, "and we hope to see ___second."
| A．A; the | B．A; a | C．The; / | D．The; a |
It is hard to say what kind of person he is．Sometimes he is very friendly; at other times he ___ be very cold．
| A．can | B．must | C．will | D．shall |
In my opinion, ___ matters is not one’s looks, but one’s inner thoughts．
| A．that | B．it | C．what | D．which |
Not far from the school there was a garden, _____ owner sat in it playing chess with his grandson every afternoon.
| A．its | B．whose | C．which | D．that |