Although many measures （），the world's economy is still going down．
A: were taken
B: have been taken
C: will be taken
D: are taken
A: were taken
B: have been taken
C: will be taken
D: are taken
举一反三
- The water will be further polluted unless some measures ______. A: will be taken B: are taken C: were taken D: have been taken
- Last year some additional measures ____ to protect personal information by the company. A: are taken B: were taken C: have been taken D: will be taken
- The water will be further polluted unless some measures ________. A: will be taken B: are taken C: were taken D: had been taken
- Half of the material ___ away. A: has been taken B: are taken C: have been taken D: were taken
- Great changes _____ place since he left here. A: have been taken B: have taken C: were taken