t小型注汽锅炉主燃油管路上装有2个主燃（）。
A、电磁阀
B、电动阀
C、放空电磁阀
D、球阀
参考答案：A
The hotel wasn't particularly good, but I _______ in many worse hotels. [ ]
A. stayed
B. would stay
C. was staying
D. had stayed
下列哪一项不是婴幼儿哮喘的诊断依据
A．喘息发作≥3次
B．肺部出现哮鸣音
C．喘息症状突然发作
D．一定伴有发热
E．一、二级亲属中有哮病史
