脂蛋白密度由高到低的排列顺序是 （）

A.CM，LDL，VLDL，HDL

B.HDL，LDL，VLDL，CM

C.LDL，IDL，HDL，CM

D.CM，VLDL，LDL，HDL

E.VLDL，LDL，CM，HDL

The athlete’s family came to Beijing in August,2008 to watch him play.That was     

_____they began their contact with the  large country with a long history.

A．in which

B．at which

C．why

D．when