等词搭配，如：accomplish a historic mission 完成一项历史使命。Venture 冒险；常指商业上的冒险投机。例如：He declined the business venture. Commission 委任；代理；佣金。He often goes beyond his commission.(他时常越权。)responsibility 责任。本题译文：当航天飞机完成了它的使命，它能在大约两周内做好准备再次航行。题目6：The child enjoyed _____ up the wooden bricks then knocking them down.