---You seem to have had that car for years.

---Yes, I should sell it ________ it still runs.    

A．before

B．during

C．until

D．while

脂蛋白进行琼脂糖凝胶电泳（pH8.6电泳缓冲液）从负极到正极依次是（）

A.VLDL、LDL、CM、HDL

B.HDL、VLDL、LDL、CM

C.LDL、HDL、VLDL、CM

D.CM、VLDL、LDL、HDL

E.CM、LDL、VLDL、HDL