问题详情

What"s the main idea of the passage？
A．Everybody uses only one form. of communication.
B．Nonlinguistic language is very useful to foreigners.
C．When a language is a barrier, people will find other forms of communication.
D．Although other forms of communication exist, oral speech is .the fastest.请帮忙给出正确答案和分析，谢谢！