______ after a long walk, Henry called and said he couldn’t come．

A．Having worn out

B．Being worn out

C．To wear out

D．Worn out

一列简谐横波沿x轴传播，相距2.0m的两个质元的振动图象分别为图示中的实线和虚线，已知该波的波长λ＞2.0m，则以下说法正确的是（　　）

A．该波上质元振动的振幅为2.0cm

B．该波上质元振动的周期为0.25s

C．该波的波速可能为

D．该波的波长一定为8.0m