The young man invited the lady to dance with him, but she ______ his invitation．
| A．turned off | B．turned out | C．turned down | D．turned away |
“I haven't heard from Henry for a long time.” “What do you suppose_____ to him?”
| A．was happening | B．to happen | C．has happened | D．had happened |
Many countries, for example, Mexico and Japan, _____a lot of earthquakes.
| A．have | B．having | C．to have | D．having had |
Each of the students, hoping to pass the exam, _____the book.
| A．buying | B．having bought | C．should buy | D．to buy |
He told me the news_____, believe it or not, he had earned $1 000 in a single day.
| A．that | B．which | C．as | D．because |
The research is so designed that once _____ nothing can be done to change it.
| A．begins | B．having begun | C．beginning | D．begun |