Once upon a free a poor farmer taking a sack of wheat to the mill did not know【C1】______to

do when it slipped from his horse and fell【C2】______the road．The sack was【C3】______heavy for him to【C4】______, and his only hope was that【C5】______someone would come riding by and【C6】______a hand. It was not long【C7】______a rider appeared, but the farmers heart sank when he【C8】______him, for it was the great man who lived in a castle nearby. The farmer【C9】______have dared to ask【C10】______farmer to help, or any poor man who might have come【C11】______the road, but he could not beg a【C12】______of so great a man.【C13】______, as soon as the great man came up he got【C14】______his horse, saying "I see youve had bad luck, friend．How good it is【C15】______Im here just at the【C16】______time. "Then he took one【C17】______of the sack, the farmer the other, and between them they lifted it on the horse. "Sir," asked the farmer, "how can I pay you？ " "Easily enough," the great man【C18】______. "Whenever you see【C19】______else in trouble,【C20】______the same for him. "

【C1】

A．how

B．what

C．which

D．whether