—Why，I didn’t get you on the phone.
—We ________football on the playground when you phoned.
| A．must be playing |
| B．must play |
| C．must have played |
| D．must have been playing |
Jane established a program, ____ young people to take part in activities ____ promote greater concern for the environment．
| A．to encourage; where | B．having encouraged; where |
| C．encouraging; that | D．encouraged; which |
Last year I applied to Princeton University．I ____ they would say yes—but they did, and now here I am．
| A．never think | B．am never thinking |
| C．have never thought | D．never thought |
When ____ to feel unworthy, children often work extra hard to please their parents．
| A．to make | B．making | C．made | D．having made |
____ this may sound like a simple process, great care is needed．
| A．Since | B．Once | C．Although | D．Unless |
—I wonder why he has been acting so strangely these days．
—Recent pressure at work may ____ his behavior．
| A．account for | B．call for | C．change for | D．stand for |