Children under 12 years old in that country be under adult supervision when in a

Children under 12 years old in that country _____ be under adult supervision (监管) when in a public library.  

A. must      B. may      C. can      D. need

试题答案

A 

解析:

句意为“12岁以下的儿童必须在父母的监督下在图书馆看书”。四个选项中能够表示“必须”的只有must。故选A。