单选题 《复合题被拆开情况》 One Saturday, Mark and Jane decided to go to a hill near their village. They made some food to take along【C1】________lunch. The two friends talked and laughed【C2】________they walked. When they got close to the hill, they【C3】________see a tall tree on the top. Mark【C4】________out, "I’ll race(赛跑)you to the tree!" Both children ran as【C5】________as they could【C6】________the hill. As they arrived【C7】________the top, the children【C8】________that there were large dark clouds in the sky. "I think a storm(暴风雨)【C9】________," said Jane. The children ran down the hill quickly【C10】________ Mark’s house. Then it started to rain. Mark and Jane sat by a large window and ate their food watching the storm.《问题》：【C3】