更多"[单选题] I don’t know what they are __"的相关试题:
[单选题] I don’t think the news you told me ________ true.
A. are
B. is
C. being
D. am
[单选题] I didn’t hear what he ________ at the meeting.
A. spoke
B. told
C. talked
D. said
[单选题] Don’t drink too much coffee in the evening, ________ you won’t fall asleep.
A. and
B. or
C. but
D. so
[单选题] What did Hofman come to know when he arrived in Paris?
A. What he said in French could not be understood by people in France.
B. The French people could not speak French as well as he could.
C. He did not know how to talk to a French woman.
D. He knew little of the French grammar.
[单选题] Please don't ________ again.
A. be later
B. late
C. later
D.be late
[单选题] Let's________the picture. What can you see in it?
A. look at
B. see
C. look
D. look like
[填空题]已知i1=30sin100πt+15°)A,i2=40sin100πt+105°)A,则i1+i2=（ ）A )。
[单选题]若分部将i1＝10sin（314t＋90°）A、i2＝10cos（314t－90°）A和i3＝10A三个电流分别通过同一个电阻，通电时间相等，其发热量最大的是
A.i1
B.i2
C.i3
D.一样
[单选题]若将i1=10sin（314t+90o）A，i2=10sin(314t-90o)A,i3=10sin314tA三个电流分别通过同一个电阻，通电时间相等，其发热量最大的是( )。
A.
1
B.
2
C.
3
D.
三者相等
[单选题]已知:i=100sin(ωt+30°)A，t=0时，i等于()A。
A.-100
B.-50
C.50
D.86.6
[单选题] I can’t go to the cinema with you. I must ________ the lessons first.
A. go on
B. go over
C. go down
D. go into
[单选题][T]A-C-I-002 4 2 4
若将探测时间、延迟时间、反应时间分别用T探测、T延迟、T反 应 表示,则三者之间应满足下面的时间关系:( ) 。
A.( T探测 + T反应 )= T延迟
B.( T探测 + T反应 )> T延迟
C.( T探测 + T反应 )≥ T延迟
D.( T探测 + T反应 ) < T延迟
[单选题]若I1＝8sin(Ωt＋10°)A，I2＝6sin(Ωt＋30°)A，则其二者合成后(____)。
A.幅值等于14，相位角等于40°
B.i＝10sin(Ωt－20°)
C.合成电流i＝I1＋I2，仍是同频率的正弦交流电流
D.频率和相位都改变，是非正弦交流电流
[判断题]BD001 冷作结构的零件尺寸公差，除设计图样、工艺文件有特殊要求的，一般可按 I T13～I T14( )级公差来确定。
A.正确
B.错误
[填空题]某一正弦交流电的表达式i=I1sin(ωt+30°)A，I1={#X1#}A。试求其最大值Im=_____A、有效值I=_____A。(计算结果保留小数点后两位)
[单选题]当t = 0.01s时，电流 i =10sin317t的值为（ ）A。
A.3.14
B.10
C.0
D.-10
[单选题]当t = 0.01s时，电流 i =10sin315t的值为（ ）A。
A.3.14
B.10
C.0
D.-10
[单选题]当t = 0.01s时，电流 i =10sin316t的值为（ ）A。
A.3.14
B.10
C.0
D.-10
