—Have you graduated from Shandong University?
—Yes.I________there for 4 years.
| A．studied | B．have studied |
| C．had studied | D．have been studying |
-----They used to be good friends, but now they are like strangers. ----- How _____ this ______?
| A．were; come about | B．did; come about |
| C．were; taken place | D．were; happened |
This new-type machine____________ little room.
| A．takes up | B．is taken up | C．has been taken up | D．is taking up |
The cattle _______ grazing on the grass.
| A．were | B．was | C．be | D．is |
Such a problem is＿＿＿＿difficult for a primary school student ＿＿＿.
| A．so； to work | B．very too； to work out |
| C．rather too； to work out | D．quite too； to answer |
— What does the sign over there read?
—“No person __________ smoke or carry a lighted cigarette，cigar or pipe in this area.”
| A．will | B．may |
| C．shall | D．must |