With many forests being destroyed, huge quantities of good earth ______ each year.
| A．is washing away | B．is being washed away |
| C．are washing away | D．are being washed away |
I failed in the final exam last term and only then ______ the importance of studies.
| A．I realized | B．I had realized | C．had I realized | D．did I realize |
I hated practicing, but I stuck_______ _it and now I can play pretty well.
| A．to do | B．to doing | C．do | D．doing |
I smell something ________in the kitchen. Can I call you back in a minute?
| A．burning | B．burnt | C．being burnt | D．to be burnt |
Is that a book in farming? ________,I want to borrow it.
| A．So it is | B．If so | C．So is it | D．So if |
Catching________ sight of a policeman coming here, the thief hurried out of________ sight.
| A．/ ; / | B．the ; / | C．/ ; the | D．the ; the |