一根矩形截面梁的高度为h，宽度为b，则其抗弯截面模量为（）
A.bh2/6
B.b（2h）2
C.2（bh2/6）
D.2（bh3/12）
参考答案：A
One advantage of playing the guitar is it can give you a great deal of pleasure.
A．how
B．why
C．when
D．that
