Everyone knows that________ is dangerous to play with fire, but________ is difficult is to prevent children from playing with fire.
| A．it; what | B．what; what | C．what; it | D．it; it |
.---Sorry, Mum. I’ve lost my pen again.
I_____it! You never remember to put your things away after using them.
| A．knew | B．know | C．have known | D．will know |
---Has Tom finished his job yet?
---I have no idea of it; he _____ it this morning.
| A．has been doing | B．had been doing | C．did | D．was doing |
I should very much like to have gone to the party, but______.
| A．I'm not invited | B．I won't be among the invited |
| C．they won't invite me | D．they didn't invite me |
He has much money at the beginning of every month, but by the end of it he_____ have little left.
| A．can | B．will | C．must | D．should |
.Sally______ a book about China last year but I don't know whether she has finished it.
| A．wrote | B．has written | C．was writing | D．had written |