---Why did you stop writing?
--- I _____ my writing paper.
| A．ran out of | B．have been used up |
| C．have used up of | D．have run out |
—I wonder if you could go with me to the shopping mall.
—Don’t disturb me. I ______ my experiment report all the morning and haven’t finished yet.
| A．wrote | B．was writing | C．have written | D．have been writing |
—Would you mind if I open the door?
—______
| A．It doesn’t matter. | B．No, go ahead. |
| C．Yes, please. | D．Never mind. |
She was so angry that she rushed out into the rain ______ I could stop her.
| A．when | B．until | C．before | D．after |
While listening to the concert, the audience is required to remain ______ and keep quiet.
| A．seated | B．to be seated | C．seating | D．to seat |
It is important to know about the cultural differences that______ cause problems．
| A．must | B．may | C．dare | D．shall |