You will never gain success ______ you are fully devoted to your work.
| A．when | B．because |
| C．unless | D．after |
Come and visit me whenever _______.
| A．you are convenient | B．you will be convenient |
| C．it is convenient for you | D．it will be convenient for you |
_______will Mr. Black be able to regain control of the company.
| A．Only by working hard | B．Only he works hard |
| C．With hard work | D．Only if work hard |
This type of computer is of great help and I’ll buy it _______.
| A．however may it cost | B．no matter how much it cost |
| C．however much it is cost | D．however much it may cost |
______ this new style of hat---maybe you will find it suitable for you.
| A．Having tried | B．Trying | C．Try | D．To try |
The train _______ at the present speed until it reaches Beijing at about 6 :30 am.
| A．went | B．has gone | C．goes | D．will be going |