现浇混凝土空心楼板肋间距宜小于（）板厚。
A、2倍
B、1.5倍
C、3倍
D、5倍
参考答案：A
跳马一般分为几个阶段进行分析？（）
A、5个
B、6个
C、7个
D、8个
Which of the following is true about the picture().
A.It doesn’t cost much.
B.It would not be good enough for "my" room.
C.It costs about 30 dollars.
D.It is very famous.
