【多选题】莫扎特的《G大调弦乐小夜曲》共四个乐章,分别是( )。
【简答题】用所给动词的适当形式填空。 A smaller number of parents send messages 1 ( ask ) for suggestions for their sons or daughters. I was at Harvard for three years before 2 (drop) out. We discourage 3 (drop)out. 4 ( have...
【单选题】一平面简谐波沿x轴负方向传播.已知x = x0处质点的振动方程为y=Acos(ωt+φ0).若波速为u,则此波的表达式为
A.
y =Acos{ ω [ t -( x 0 -x ) / u ]+ φ 0 }
B.
y =Acos{ ω [ t -( x-x 0 ) / u ]+ φ 0 }
C.
y =Acos{ ω [ t+ ( x 0 -x ) / u ]+ φ 0 }
D.
y =Acos{ ω [ t+ ( x-x 0 ) / u ]+ φ 0 }
【单选题】国产轻柴油的牌号是根据柴油的( )来划分的。
【单选题】一平面简谐波沿x 轴负方向传播.已知 x = - 1 m 处质点的振动方程为y=Acos( w t+ ) ,若波速为 u ,则此波的表达式为
A.
y= Acos[ w ( t+(x+1)/u)+ ]
B.
y= Acos[ w( t+x/u)+ ]
C.
y= Acos[ w( t-(x+1)/u)+ ]
D.
y= Acos[ w( t+(x-1)/u)+ ]
【简答题】S tudents ’ pressure sometimes comes from their parents. M ost parents are well (36) ________ , but some of them aren ’ t very helpful with the problems their sons and daughters have in (37) ________ ...
【简答题】FileInputStream实现对磁盘文件的读取操作,在读取字符的时候,它一般与_________和_________一起使用。