---Helen, will you be at the party tonight?
---Yes, but I have so much homework to do that I really__________.
| A．can’t | B．mustn’t | C．won’t | D．shouldn’t |
When first __________ to the market, the computer software was not a success due to its complexity in operation.
| A．introducing | B．being introduced |
| C．introduced | D．to be introduced |
It’s certainly been a long time _________ we met last time.
| A．that | B．before | C．until | D．since |
Unfortunately, the element Madam Curie devoted all her life her death.
| A．to caused | B．causing | C．to be caused | D．to causing |
Out of the crowded bus , who was dressed in a black suit and waved to a woman.
| A．a tall man stepped | B．stepped a tall man |
| C．did a tall man step | D．did a tall man stepped |
With the help of high technology, in the past few years, electronic business __________to bank industry, travel industry.
| A．applied | B．have applied |
| C．had been applied | D．has been applied |