【单选题】某三相异步电动机额定转速为1460r/min,p=2,f=50hz,当负载转矩为额定转矩的一半时,其转速为
【简答题】According to a marketing executive, many students from low-income families don‘t know they could have a chance of going to an elite university. 查看材料
【单选题】What does Mr. Leonard expect from those low-testing students?
C.
Respectfulness and discipline.
D.
Willingness to learn by themselves.
【简答题】他什么时候有空呢 ? What time is c_______ for him ?
【单选题】The tuition fees are ______ to students coming from low-income families. [2007]
【单选题】下列关于苯的叙述正确的是( )。
A.
苯的分子式为 ,它不能使酸性 溶液褪色,属于饱和烃
C.
在催化剂作用下,苯与液溴反应生成溴苯,发生了加成反应
D.
苯分子为平面正六边形结构,6个碳原子之间的价键完全相同
【单选题】下 列关于苯的叙述中, 不正确的是
C.
苯环上的 C 原子采用 sp2 杂化方式与邻近 C 原子成键
【简答题】A.Low expectations from educators. B.ager pregnancies. C.The students are bored with their classes. D.They become prisoners.