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【简答题】
.A 、 B 两点有两个相干波源,初相差 ,振幅都为 4cm ,频率 70Hz ,波速 400m/s , AB 距离为 40m , P 为 AB 之间一点,AP:BP=1:3 , 则 A 、 B 波源到达 P 点引起的两个分振动的关系为_______(填‘同相’或‘反相’) , P 点振幅为 _______cm 。
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举一反三
【单选题】When driving, we are ________ to fasten the seat belt for safety.
A.
compelling
B.
compelled
C.
to compel
D.
compel
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【单选题】下面不属于戏曲表演来源的是()。
A.
说唱
B.
滑稽表演
C.
诗歌
D.
歌舞
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【单选题】When driving, we are ___ to fasten the seat belt for safety.
A.
compelling
B.
compelled
C.
compels
D.
compel
查看完整题目与答案
【单选题】When driving, we are ___ to fasten the seat belt for safety.
A.
compel
B.
compelled
C.
compels
D.
compelling
查看完整题目与答案
【单选题】关于结构化程序设计原则和方法的描述错误的是
A.
选用的控制结构只准许有一个入口和一个出口
B.
复杂结构应该用嵌套的基本控制结构进行组合嵌套来实现
C.
不允许使用GOTO语句
D.
语言中没有的控制结构，应该采用前后一致的方法来模拟
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【单选题】Good luck to you, and _____ all your wishes come true!
A.
can
B.
may
C.
must
D.
should 
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【简答题】At times we all get angry when we are driving. It might be because we are stuck in a traffic jam or stuck behind a very slow driver. It might be because we think another driver has done something very...
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【简答题】'; if ($a '; if ($a > 99) { echo 'true'; } else { echo 'false'; } echo ''; if ($a '; if ($a >= 99) { echo 'true'; } else { echo 'false'; } echo ''; if ($a == 100) { echo 'true'; } else { echo 'false';...
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【简答题】If we are driving a car or crossing a street, we will stop when the traffic lights turn red. Why do we use red rather than other colors? As we know, scattering (散射) happens when light goes through the...
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【单选题】Which of the following statement is NOT true?
A.
Irene went to Hong Kong three weeks ago.
B.
Irene did all the stuff her planned to do.
C.
Irene thought Hong Kong was very interesting.
D.
Irene wished she could be in Hong Kong much longer.
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相关题目：
【单选题】When driving, we are ________ to fasten the seat belt for safety.
A.
compelling
B.
compelled
C.
to compel
D.
compel
查看完整题目与答案
【单选题】下面不属于戏曲表演来源的是()。
A.
说唱
B.
滑稽表演
C.
诗歌
D.
歌舞
查看完整题目与答案
【单选题】When driving, we are ___ to fasten the seat belt for safety.
A.
compelling
B.
compelled
C.
compels
D.
compel
查看完整题目与答案
【单选题】When driving, we are ___ to fasten the seat belt for safety.
A.
compel
B.
compelled
C.
compels
D.
compelling
查看完整题目与答案
【单选题】关于结构化程序设计原则和方法的描述错误的是
A.
选用的控制结构只准许有一个入口和一个出口
B.
复杂结构应该用嵌套的基本控制结构进行组合嵌套来实现
C.
不允许使用GOTO语句
D.
语言中没有的控制结构，应该采用前后一致的方法来模拟
查看完整题目与答案
【单选题】Good luck to you, and _____ all your wishes come true!
A.
can
B.
may
C.
must
D.
should 
查看完整题目与答案
【简答题】At times we all get angry when we are driving. It might be because we are stuck in a traffic jam or stuck behind a very slow driver. It might be because we think another driver has done something very...
查看完整题目与答案
【简答题】'; if ($a '; if ($a > 99) { echo 'true'; } else { echo 'false'; } echo ''; if ($a '; if ($a >= 99) { echo 'true'; } else { echo 'false'; } echo ''; if ($a == 100) { echo 'true'; } else { echo 'false';...
查看完整题目与答案
【简答题】If we are driving a car or crossing a street, we will stop when the traffic lights turn red. Why do we use red rather than other colors? As we know, scattering (散射) happens when light goes through the...
查看完整题目与答案
【单选题】Which of the following statement is NOT true?
A.
Irene went to Hong Kong three weeks ago.
B.
Irene did all the stuff her planned to do.
C.
Irene thought Hong Kong was very interesting.
D.
Irene wished she could be in Hong Kong much longer.
查看完整题目与答案