题目内容：

The students there had to believe what the teacher told them because they had no other sources o...
The students there had to believe what the teacher told them because they had no other sources of information ___
A.however
B.besides
C.otherwise
D.so

优质解答

B
however的出现,其后一般伴随逗号
otherwise是否则的意思
so一般不用于句尾