The headmaster, together with the teaching staff, are away on holiday 

If she__________a car, she would go out in the evening.

The bones of mammals, not alike those of other vertebrates, show a high degree of differentiation.

Only a few mineral can resist weathering by rainwater, which is a weak acid.

A number of wildlife reserves have been established__________endangered species can have a

chance to survive and develop.

During the week of national tourism festival, we had visitors__________from all over the country.

The price of petrol has raised so rapidly that we decided to use the bus.