汽车发动机气门弹簧工作时,其变形是() ["A、刚性变形 ","B、永久变形 ","C、塑性变形 ","D、弹性变形"]
测定汽油辛烷值的目的是判断汽油()的优劣。 ["汽化性能","抗爆性能","动力性能","质量"]
先天愚型表现为() ["智力低下,特殊外貌,关节过伸,通贯手","智力低下,特殊外貌,四肢粗短,躯干较长","智力低下,特殊外貌,听力障碍,肝脾肿大","智力低下,表情呆滞,反复抽搐,尿发霉臭味","智力低下,表情呆滞,面色蜡黄,舌头震颤"]
肠道致病菌特征:()。 ["抗原结构复杂,均有H、O抗原","在SS琼脂上为无色不透明菌落","多数分解乳糖","可用免疫血清鉴定分型","革兰阴性杆菌"]
职业会计人的行为准则是() ["会计法律制度","会计职业道德","企业伦理","会计准则"]
简述溢流染色。