单项选择题
【案例分析题】
After lunch，without their parents’【C1】______，the two boys set off’to explore the beach which beyond the headland（岬）.They had【C2】______their young sister to【C3】______，saying that the long【C4】______would be too【C5】______for her.Once they had got beyond the headland，the beach stretched（延伸）away endlessly before them.It was like【C6】______a new world.Here and【C7】______along the beach there were lots of sea -creatures.The two boys kept searching everywhere for those【C8】______things.
The afternoon passed【C9】______.The sun was already【C10】______when the boys reluctantly【C11】______to make their way homewards.But long before they reached the headland，they could【C12】______that the tide had come in so far that they were now【C13】______from either end of the beach.Their only【C14】______of returning back was to find a way up the cliff（悬崖）nearby.
They soon found a narrow path【C15】______to the cliff top.But halfway up，their only【C16】______was blocked by a【C17】______rock which they could not climb【C18】______.The two boys had to shout at the top of their voice，【C19】______that someone【C20】______come to help them out.Just then，to their great surprise，their father appeared over the top of the rock，and with him were two policemen.One of them climbed down with a rope which was lowered over the rock.The two boys were then pulled up to safety and thus saved from spending a miserable night on the cliff.
【C1】（）
