By using the methods of spectral analysis, astronomers ____ to learn a great deal about the sun.? is able;;|will be able;;|has been able;;|have been able
举一反三
- I wish I ________ to talk this over with him when he was here last night. A: had been able B: have been able C: were able D: should be able
- Were it not for friction, we ( ) walk on this earth of ours. A: should not have been able to B: would not be able to C: were not able to D: are not able to
- Were it not for friction (摩擦力), we ______walk on this earth of ours. ( ). A: were not able to B: should not have been able to C: would not be able to D: are not able to
- I hope ___ the little___ I have been able to do has been of some use
- I've enjoyed ____ to talk with you. A: to be able B: being able C: to been able D: of being able