【判断题】中频弯管机是属于管子热煨的一种方法,是用电能通过感应圈来加热管子的弯曲部位,一般煨曲Ф114*4的管子,调整直流电源为350~450V;中频电压为200~300V;中频电流为200~300A比较适宜。
【多选题】在丙酮酸羧化支路中,使丙酮酸转变为磷酸烯醇式丙酮酸,需下列酶
【判断题】表单域一定要放在form元素中( )A. 对 B. 错
【单选题】法律和道德是维护社会秩序的两种基本手段。下列关于两者关系的说法中,正确的是( )
A.
法律是道德形成的基础,能够为道德规范的制定提供依据
B.
凡是道德所反对和谴责的行为,必定是法律所制裁的行为
C.
法律的调节更具有广泛性,能够渗透到道德不能调节的领域
D.
凡是法律所禁止和制裁的行为,通常也是道德所反对的行为
【单选题】Why does the author say that nothing was wasted before the invention of fridges?
A.
People would not buy more food than was necessary.
B.
Food was delivered to people two or three times a week.
C.
Food was sold fresh and did not get rotten easily.
D.
People had effective ways to preserve their food.
【单选题】在进行避雷器工频放电实验时,要求限制放电时短路电流的保护电阻,应把适中电流的幅值限制在()以下。