In many countries now seat belts are ( ) for the driver and front seat passengers at least.
A、necessary
B、in demand
C、in need
D、compulsory
【正确答案】：D
【题目解析】：考核单词和短语含义，根据句子含义判断选择D，in need 需求，in demand 要求，necessary 必须的，compulsory 强制的，句子含义是在许多国家，司机和前排乘客至少必须系上安全带。
