Reading several books on that subject, Bill considered himself an expert.

Mercury and alcohol are widely used in thermometers because their volume increases uniform with temperature.

By the mid-nineteenth century, land was such expensive in large cities that architects began to conserve space by designing skyscrapers.

If today is Sunday, we would have a lot of fun at the camping site.

Although most species of small birds gather in groups at feeders provided by bird-watchers, the bright red cardinals usually appears alone or with its mate.

I think she will be suitable for the work because she has been working like a teacher for a long time.

Little have people done to alleviate the sea pollution caused by the factories in central Vietnam, haven’t they?

Ecologists are trying to preserve our environment for future generations by protecting the ozone layer, purifying the air, and have planted the trees that have been cut down.

Did you say that you will have a lot of things to do the following week?

It is difficult to write rules that tell exactly when we should apologize, and it is not difficult to learn how to do it.

My father asked me where had I gone the night before.

Ralph wishes that he went to the bank this morning before he went to work.

Hardly did he enter the room when all the lights went out.

English is speaking in many countries in the world.

In a federal form of government like that of the United States, power is divided between the legislative, executive, and judicial branches.

A child of noble birth, his name was famous among the children in that school.

In spite of my father is old , he gets up early and does morning exercise.

By the turn of the century, most of the inventions that were to bring in all the comforts of modern living has already been thought of.

Robots in the home might not be enough creative to do the cooking, plan the meal and so on.

He was very surprised when he visited London, in that the drivers always drive on the left hand side of the street.

She did not know where most of the people in the conference was from.