【单选题】—_____ you _____ Kate’s letter yet? —Yes. I _______ it for several days. [ ]
A.
Did…receive, have received
B.
Did… receive, have had
C.
Have… received, have received
D.
Have received, have had
【单选题】传感器输出量增量Δy引起输出量增量Δy的相应输入增量Δx之比称为( )
【判断题】正象同构就是充分利用一个物形的某一局部与另一个物形的相似之处偷梁换柱式地将之替换而组成为一个新的形象。
【单选题】—How did your mathematics exam go? —I thought I ,but in fact I fell behind in the class.
A.
should have been the top 10
B.
could have been the top 10
C.
may have been the top 10
D.
need have been the top 10
【单选题】教师劳动的复杂性首先是由( )的复杂性决定的。
【判断题】Whatisyourhobby?(你的业余爱好是什么?)。