It is the in China that people often shake hands when they meet someone for the first time

问题补充：

It is the in China that people often shake hands when they meet someone for the first time.

A．custom

B．habit

C．hobby

D．favor

答案：

解析：考查词义辨析。Custom 风俗习惯，habit 个人养成的习惯，hobby 业余爱好，favor支持，句意：在中国，当人们第一次见面的时候经常握手这是一个风俗习惯。所以选A。