【单选题】对某电路中一个NPN型硅管进行测试,测得 ,则此管工作在( )。
【单选题】水泥的抗压强度最高,一般是抗拉强度的( )
【简答题】I. Contractions:1)_______ 2)_______ 3)_______ 4)_______
【简答题】i. Contractions: 1. ________ 2. ________ 3. ________ 4. ________
【单选题】What does a man do when he cannot get exactly what he wants?
A.
He usually does not buy anything.
B.
At least two of his requirements must be met before he buys.
C.
He buys similar things of the colour he wants.
D.
So long as the style. is right, he buys the thing.
【多选题】商品包装的种类按商品包装层次划分分为()。