--WhatareMexicanssupposedtodowhentheymeet

問題詳情：

--What are Mexicans supposed to do when they meet ______ the first time?

--They are supposed to shake hands.

A. on                    B. for                    C. among              D. at

【回答】

B

知識點：介詞和介詞短語

題型：選擇題