用不定冠词an，例如：
1、He didn't even have the intelligence to call for an ambulance.他连呼叫救护车的头脑都没有。
2、The injured were rushed to hospital in an ambulance.救护车把伤员火速送往医院。
3、Someone phone for an ambulance!谁打电话叫辆救护车！
用不定冠词an，例如：
1、He didn't even have the intelligence to call for an ambulance.他连呼叫救护车的头脑都没有。
2、The injured were rushed to hospital in an ambulance.救护车把伤员火速送往医院。
3、Someone phone for an ambulance!谁打电话叫辆救护车！
