The hill ____ is covered with tress is called Huang Hill.
| A．of which top | B．whose the top |
| C．whose top | D．top which |
It is I____singing in the garden.
| A．who are | B．who is | C．that am | D．that is |
It was____the old worker came that we____the experiment.
| A．until;didn’t begin | B．not until;began |
| C．until;began | D．not until;didn’tbegin |
____be careful when crossing the street!
| A．Must | B．Should | C．Ought to | D．Do |
___come again.
| A．Do | B．Can | C．May | D．Did |
I____see him yesterday.
| A．really | B．do | C．did | D．does |