Ever since my brother graduated from the university, he _______ in the present company for 15 years and he is now chief engineer of the company.
| A．worked | B．has been working |
| C．is working | D．works |
. --- Excuse me, but I want to use your computer to type a report.
--- You _____have my computer if you don't take care of it.
| A．shan't | B．might not | C．needn't | D．shouldn't |
--- Who is the girl standing over there?
--- Well, if you ______ know, her name is Mabel.
| A．may | B．can | C．must | D．shall |
Children under 12 years of age in that country _____ be under adult supervision when in a public library.
| A．must | B．may | C．can | D．need |
--- Isn't that Ann's husband over there?
--- No, it ______ be him---I'm sure he doesn't wear glasses.
| A．can't | B．must not | C．won't | D．may not |
Mr White____at 8:30 for the meeting, but he didn't show up.
| A．should have arrived | B．should arrive | C．should have had arrived | D．should be arriving |