根据所给汉语，写出句中所缺的词语。

1.You could                  (自愿服务) in a hospital.

2.I'd like to help                    (无家可归) people.

3.We often visit                   (小学的，初级的) schools and help the teachers.

4.A girl won a million                 (美元) in the lottery.

5.Before you borrow something from a friend, you'd better ask his or her                 (许可).

患儿，男，10个月，平时发育营养正常，人工喂养。3天来腹泻，大便每日20余次，蛋花汤样，伴低热，偶有呕吐，1天来尿少，6小时来无尿。查体：精神萎靡，口干，眼窝及前囟凹陷，皮肤弹性差，四肢凉，BP64／40mmHg，血清钠134mmol／L。

该患儿脱水的程度是（）。

A.轻度脱水

B.中度脱水

C.重度脱水

D.低渗脱水

E.高渗脱水