【单选题】Part 2 task1 Passage3, question1
A.
Because they hated each other
B.
Because they had a bet
C.
Because they had a quarrel
D.
Because they lost their way
【简答题】试求下列函数的拉氏变换. (1)f(at-b)u(af-b); (2)e-tu(t-1).
【单选题】车站技术管理和作业组织应在( )中规定。
【单选题】已知数列{a n }既是等差数列又是等比数列,则这个数列的前n项和为 [ ]
【判断题】交流耐压试验电压波形应是正弦或接近正弦,两个半波应完全一样,且波顶因数即峰值与有效值之比应等于√2±0.07。( )
【简答题】《安规》规定,凡在距离地面()m以上的处所进行作业,均称为接触网高空作业。
【简答题】You (stand)______ several feet away if you wish to get the full effect of the picture.
【单选题】Part 2 task1 Passage1, question2:
A.
Richard lent some money to Michael
B.
Michael helped Richard build his house
C.
Michael invited Richard to fly kites
D.
Richard set fire on Michael's house
【单选题】已知数列{a n }的前n项和S n =q n -1(q∈R,q≠0),则数列{a n }( )