With trees and grass_____ about 35％ of the urban area，the city of Hefei has taken on a new look.
A．covered B．being covered C．to be covered D．covering
Process so far has been very good．______，we are sure that the project will be completed on time．
A．However B．Otherwise C．Therefore D．Besides
— When do we need to pay the balance?
— ____ September 30.
A．In B．By C．During D．Within
______ and out of breath, we reached the top of the mountain and stopped _____ the beautiful scenery.
A．Tiring, to admire B．Being tired, admiring
C．Tired, to admire D．Tired, admiring
I greeted the teacher with “ hello”, and the teacher gave me a sweet smile ______.
A．by turns B．in return
C．in turn D．for turn
Do you know the trouble he had _____ the work?
A．on finishing B．to finish
C．having finishing D．finishing
