摩西出埃及记中关于海水变化的描述，应是下列哪种地质现象的直接结果？（）
A.地震
B.海啸
C.风暴
D.火山
参考答案：B
剧场、电影院、礼堂的幕布的燃烧性能不得低于（）。
A.A级
B.B1级
C.B2级
D.B3级
— Thanks a lot, Mr. Wang. I don't know how to ________ the help you gave me during my stay here.
— It's my pleasure. Welcome to China again when you have time. [ ]
A. pay off
B. pay back
C. pay for
D. pay to
