My dream is to buy a big house.Now I live in a small house with my parents.Life of us is hard but happy.I must work hard
问题描述：
My dream is to buy a big house.Now I live in a small house with my parents.Life of us is hard but happy.I must work harder _____ I want to buy a big beautiful house when I grow up.
A until B because C if D so
答
选择B.因为.句子翻译为：我必须努力工作,因为我长大后想要买一个大的漂亮的房子.