题干
. It was great joy ________ he received the news that his lost daughter had been found.
A：because
B：which
C：since
D：that
答案(点此获取答案解析）
D
A：because
B：which
C：since
D：that
千米？设李老师每小时走x千米，依题意，得到的方程是（ ）