Glad to see you back. How long in Russia?
| A．did you stay | B．have you stayed | C．were you staying | D．have you been staying |
About ____ of the teachers in our school ____ young people under thirty.
| A．two-five, are | B．second-fifth, is | C．two-fifths, are | D．two-fifth, is |
___Mr Chen is waiting outside to speak to you. He appears to be quite ___ important person.
| A．/. an | B．A, an | C．The, the | D．The, / |
Suan!Where have you been? You have no idea ___ worried I was.
| A．how | B．that | C．that how | D．what |
—We all had a lot of fun at the barbecue yesterday. Pity you weren’t there.
—I really should have gone with you but I _____ on some remaining problems.
| A．worked | B．was working | C．would work | D．would have worked |