I was really too busy with my homework and I couldn't help ____________
housework.
| A．doing | B．do | C．did | D．done |
Mary is one of the brightest students who_________ from New York University.
| A．is graduated | B．have graduated |
| C．has graduated | D．are graduated |
Mary is short__________ her brother is very tall.
| A．still | B．nor | C．while | D．when |
--Whose advice do you think I should take?
--___________.
| A．You speak | B．That's it |
| C．It’s up to you | D．You got it |
__________ you understand the rule, you will have no further difficulty.
| A．While | B．Once | C．Though | D．Unless |