在人身保险合同中，一般不能变更的是（）。
A.投保人
B.被保险人
C.受益人
D.保险代理人
参考答案：B
Only when________the data again________that there was a mistake. [ ]
A. they had studied；did they realize
B. they had studied；realized they
C. had they studied；did they realize
D. had they studied；realized they
青年志愿者注册的基本条件有哪些？
