________, it began to rain unexpectedly.
| A．While cleaning the machine |
| B．To clean the machine |
| C．He was cleaning the machine |
| D．While he was cleaning the machine |
For many Beijingers ,dreams of living in ______green area are becoming ______reality .
| A．a; a | B．the ;the | C．不填；不填 | D．不填; a |
______I used to go mountain—climbing every summer .
| A．at a time | B．at one time | C．At times | D．At the same time |
Liping works very hard at his lessons .He didn’t get the first place in the exam ,_______.
| A．though | B．yet | C．however | D．although |
John is good at his job but she seems to ______confidence.
| A．lack | B．short | C．be short | D．lack in |
Though ______money ,his parents managed to send him to university.
| A．lacked | B．lacking of | C．lacking ( vt.) | D．lacked in |