How did the author come to notice old women carrying a big load of firewood （）

A.it is important to protect the forests

B.it is necessary to find substitutes for wood

C.why the Chinese changed their way of cooking

D.what problems a big population is causing China today

A．To show that the process of smelting iron was expensive

B．To illustrate the impact of forest fires on the iron industry

C．To point out that the iron industry had to pay high taxes

D．To emphasize that large areas of woodland were eliminated

A．all these places were too far away for them to go

B．it was impossible for them to go and get back in one day

C．they were not old enough to take such a trip

D．they were not permitted to go to these places

A．To remind readers that the colonial era ended in warfare.

B．To give an example of a product made from wood consumption.

C．To illustrate some negative aspects of some industrial processes.

D．To suggest that wood was not the only important product of the colonies.

A．To remind readers that the colonial era ended in warfare.

B．To give an example of a product made from wood consumption.

C．To illustrate some negative aspects of some industrial processes.

D．To suggest that wood was not the only important product of the colonies.

A．To remind readers that the colonial era ended in warfare．

B．To give an example of a product made from wood consumption．

C．To illustrate some negative aspects of some industrial processes．

D．To suggest that wood was not the only important product of the colonies．

A．The heavier the wood is, the better the boat is.

B．The stronger players are more likely to be chosen in the dragon boat race.

C．Good oarsmen can drive the boat in perfect direction.

D．The final result of the race is dependant on three conditions.

A．Nature

B．Raven

C．Walden, or Life in the Woods

D．Song of Myself