杠铃主要锻炼（）。
A.骨骼肌
B.平滑肌
C.腓肠肌
D.各大肌肉群
E.关节
参考答案：D
It doesn’t matter ________ you take it seriously, for _______ matters is that he can realize it.
A．whether; that
B．that; what
C．whether; what
D．that; that
