While you are hurrying to the airport, _______in a heavy traffic jam in a taxi is quite an unpleasant experience．
| A．having caught | B．being caught | C．caught | D．having been caught |
Mother was busy washing dishes ________________ Father was watching TV．
| A．until | B．if | C．since | D．while |
Shanghai is the first city in the world _____________ a high-speed maglev train，from the city to Pudong Airport．
| A．building | B．having built | C．to have built | D．built |
—Is Tom still smoking?
—No．By next Saturday he _____________ for a whole month without smoking a single cigarette.
| A．will go | B．will have gone | C．goes | D．has been going |
While reading an interesting story book in my room，______________.
| A．the light suddenly went out |
| B．the doorbell rang |
| C．someone was shouting outside |
| D．I heard someone shouting outside |
Mr．Black is willing to do ______________ Mrs．Black tells him to do．
| A．whichever | B．however | C．whatever | D．whenever |