American students take part in a wide variety of after-school activities _______ they develop their social skills.
| A．where | B．which | C．that | D．what |
Why the explosion occurred was ____ the laboratory attendant had been careless.
| A．for | B．because | C．since | D．that |
________ one foot before the other, slowly and purposefully, the deer walked up to_______ I was _______.
| A．Put, where, seated |
| B．Putting, the place where, seating |
| C．Put, the place in which, sitting |
| D．Putting, the place where, sitting |
This field of scientific research remains________.
| A．to be untouching | B．being touched |
| C．to be untouched | D．untouched |
The teacher just took down the names of the students _______ during the exam.
| A．caught cheating | B．caught to cheat |
| C．catching cheating | D．to catch cheating |
______ to get a seat for the concert, he didn’t mind standing in a queue all night.
| A．Determine | B．To be determined |
| C．Determined | D．Being determined |