患者，女，22岁，颅脑外伤后出现剧烈头痛、频繁呕吐，意识障碍程度逐渐加深，以下护理措施哪项是错误的（）。

A.抬高床头15°～30°

B.频繁呕吐时，予以禁食

C.意识不清及咳痰困难者作气管切开

D.便秘时行高位灌肠以疏通大便

E.每日补液量少于2000ml

He is rather difficult to make friends with, but his friendship, ____, is more true than any other.

A．once gained

B．when to gain

C．after is gained

D．while gaining