皮皮学,免费搜题
登录
搜题
【简答题】
如果入射波的方程是y 1 =Acos2π(t/T+x/λ),在x=0处发生反射后形成驻波,反射点为波腹,设反射波的强度不变,则 反射波的方程式为 , 在x= 2λ/3处质点合振动的振幅等于 。
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
.
..
皮皮学刷刷变学霸
举一反三
【单选题】1)school uniforms should be mandatory for all students for a number of reasons. 2)First of all, uniforms make everyone equal. 3) In this way, the "rich" kids are on the same level as the poor ones. 4)...
A.
sentence 1)
B.
sentence 7)
C.
sentence 3)
D.
sentence 4)
【单选题】look forward to
A.
查找
B.
期望
C.
小心
D.
留下
【简答题】完成句子。 1. 当前我们要更加重视校园安全问题。 We must pay attention to the problem of the in the school at present. 2. 所有的学生都应该坚信自己能够上理想的高中。 All the students should in themselves that they can go to the ideal high school...
【简答题】Most students have biology classes in the classrooms or the labs in China.But several days ago,I had a biology class outside in my American schoo1. My biology teacher,Mr.Kwak,divided us into three gro...
【单选题】To save money, some schools choose to ______.
A.
take the shortest routes
B.
shorten the school week
C.
give drivers better training
D.
use fuel-efficient buses
【单选题】We can’t feel thatwe are going forward as everythjng us is moving thesame speed .
A.
. around ; at       
B.
. around ; with     
C.
. before ; at           
D.
. with ; in
【简答题】短文改错。 此题要求改正所给短文中的错误。对标有题号的每一行作出判断: 如有错误(每行只有一个错误),则按下列情况改正: 此行多一个词:把多余的词用斜线( / )划掉,在该行右边横线上写出该词,并也用斜线划掉。 此行缺一个词:在缺词处加一个漏字符号(∧),在该行右边横线上写出该加的词。 此行错一个词:在错的词下划一横线,在该行右边横线上写出改正后的词。 注意: 每处错误及其修改均仅限一词。 I'd...
【简答题】根据句意及首字母补全单词,使句意完整。 1. Why didn't you come to my birthday party? Because I had a music l________. 2. This pair of shoes is too big. Do you h ave  a________ pair? 3. There is going to be a piano c_____...
【单选题】The students are looking forward to a good result in the final examination, aren’t they?
A.
getting
B.
have
C.
has
D.
get
【单选题】关系模式3NF是指
A.
满足2NF且不存在非主属性对关键字的传递依赖现象
B.
满足2NF且不存在非主属性对关键字的部分依赖现象
C.
满足2NF且不存在非主属性
D.
满足2NF且不存在组合属性
相关题目: