14. Since 1970, millions of enthusiasts ____Vitamin C, which they believe can remedy the common cold.
A: A. have taken
B: B. have been taken
C: C. havebeen taking
D: D. have taking
A: A. have taken
B: B. have been taken
C: C. havebeen taking
D: D. have taking
举一反三
- Since 1970, millions of enthusiasts ( ) Vitamin C, which they believe can remedy the common cold.
- A) be taking place C) be taken placeB) take place D) have taken place A: take place B: be taking place C) be taken place C: have taken place
- By the time you arrive at the airport in an hour, the plane________. A: will be taking off B: will have taken off C: will have been taking off D: will take off
- I’m really sorry to______your valuable time. A: have taken B: be taking C: have had taken
- Great changes _____ place since he left here. A: have been taken B: have taken C: were taken