Every year lots of trees ________ to make our country more beautiful.
A．is planted B．was planted
C．are planted D．were planted
How kind you are! You always do what you can ________ me.
A．help B．helping C．to help D．helps
---I have finished my homework already, Mum.
--- When ________ you ________ it?
A．did; finished B．did; finish
C．have; finished D．were; finishing
Lucy is ________ girl of the twin sisters.
A．tall B．taller C．the taller D．the tallest
---How did you work out the difficult chemistry problem?
--- I worked it out by ________.
A．working with a group B．think very hard
C．ask the teacher for help D．doing oneself
By the time we rushed to the hall, the party ________ for ten minutes.
A．had begun B．began C．was on D．had been on.
