_________ much I dislike the idea of begging in the street, we should still show consideration for those who are in difficult situations.

A．However

B．How

C．Whatever

D．No matter

液压泵A接通、B关断，刹车时使用的液压是来自：（）.

A.蓄压瓶

B.A系统

C.A系统和蓄压瓶

D.备用液压泵