The house is lighted ____ electric light.

It's too late to go to the basketball match now, ____, it's beginning to rain.

________its low cost, the appeal of iron as a building material lies in its strength, its resistance to fire, and its potential to span long distances.

We offered these students a summer course , aimed _____ improving their spoken English．

________cleaning the yard and making up the beds for the  old，we also read newspapers for them and had chats with them.