Why are the archaeologists interested in dendrochronology？A．They can measure constructions

What may lead to the differences among the rings of the same tree?

A．The weather.

B．The exposure to sunlight.

C．The nutrition provided by the soil.

D．The time span.

What happens during the natural growth of a tree each year?

A．Their rings become lighter in color.

B．They have one more ring of wood.

C．They become more precious.

D．Their rings get closer and closer.

What did Daniel Hayes invent?

A．A single-engine fire truck.

B．A water-powered fire truck.

C．A record player.

D．A circular ladder holder.

What was used to power the water pump on the Joe Ross?

A．Gas.

B．Horses.

C．Steam motor.

D．Oil motor.

What is the tour for today mainly about?

A．Urban fire fighting.

B．American fire fighting innovations.

C．The history of fire.

D．The Great San Francisco Fire fighting.

What is the passages main idea?

A．Thousands of people were punished because of salt.

B．The uses and importance of salt in history.

C．Salt was important in history.

D．Nobody knows when salt began to be used.

How would a man be punished if he took more than his share of salt in the 16th century?

A．Lose all his salt.

B．Be thrown into prison.

C．Lose an ear.

D．Lose an eye.

What was salt used to do in Egypt thousands of years ago?

A．To punish people who had broken the law.

B．To keep dead bodies from decay.

C．To make chemicals.

D．To make fish soup.

What might be the possible reason for using anold method to construct the building?

A．It was inexpensive.

B．It was time-saving.

C．It was elegant.

D．It was well-known.

How were the blocks fastened?

A．The blocks were fastened with concrete.

B．The blocks were fastened by using an old method

C．The blocks were fastened by nails.

D．The blocks were not fastened very tightly.