It is not easy for him to understand the local people,___he is a new comer.

问题描述:

It is not easy for him to understand the local people,___he is a new comer.
A although B however C or D since

选D
这上下文表示的是因果关系,对于他来说,了解本地人并不容易,因为他是新来的.
A although 虽然 表转折
B however 但是 表转折
C or 或者,否则 也有表转折的意思