a用在以辅音字母开头，或以读做辅音的元音字母开头的单词前面。例句：
A man in a crash helmet was mounting a motorcycle.
一个戴着防撞头盔的男子正骑上一辆摩托车。
扩展资料
A schoolgirl rushed into a burning apartment to save a mans life.
一名女学童冲进一栋着火的`公寓去救一个男子的命。
A personal diet plan is devised after a consultation with a nutritionist.
经向营养师作咨询后，一份个人饮食方案设计出来了。
A lion is a dangerous animal.
狮子是猛兽。
As a teacher, hes a disaster.
他当老师压根儿就不称职。
