【单选题】如图所示,设S1、S2为两相干光源发出波长为l的单色光,分别通过两种介质(折射率分别为n1和n2,且n1>n2)射到介质的分界面上的P点,己知S1P =S2P= r,则这两条光的几何路程Dr, 光程差d 和相位差Dj 分别为 [ ]【图片】
A.
D r = 0 , d =0 , D j = 0
B.
D r = ( n 1 - n 2 ) r , d =( n 1 - n 2 ) r , D j =2 p ( n 1 - n 2 ) r / l
C.
D r = 0 , d =( n 1 - n 2 ) r , D j =2 p ( n 1 - n 2 ) r / l
D.
D r = 0 , d =( n 1 - n 2 ) r , D j =2 p ( n 1 - n 2 ) r
【单选题】Read the following paragraphs carefully and then select the most appropriate topic sentence. ________________________________ They know the difference between what is and what should be.They also know...
A.
Mentalyy healthy people take responsibilities for their own actions.
B.
Mentally healthy people are not frightened by the unknown.
C.
Mentally healthy people have a good self-image.
D.
Mentally healthy people are realistic.
【单选题】听力原文:W: Things aren't what they used to be, are they? M: No, they aren't. Everything is upside down these days, People haven't even got good manners any more. Look at the way children act. Q: What are...
A.
About children's health.
D.
About old people's health.
【判断题】“零落成泥碾作尘,只有香如故”是南宋词人陆游《卜算子,咏梅》中的名句。
【单选题】如图所示,设s1、s2为两相干光源,初相相等,发出波长为l(真空)的单色光,在两种介质中波长分别为 ,两束光在P点相遇,则P点干涉相消的条件为 1 2 3 4
【单选题】To be able to to people on their level, you must be able to understand what they need and what they are trying to convey to you.
【单选题】听力原文:W: Things aren't what they used to be, are they? M: No, they aren't. Everything is upside down these days. People haven't even got good manners any more. Look at the way children act. Q: What are...
【单选题】听力原文:W: Things aren't what they used to be, are they? M: No, they aren't. Everything is upside down these days. People haven' t even got good manners any more. Look at the way children act. Q: What ar...
A.
About children's health.
D.
About old people's health.
【单选题】People become quite illogical when they try to decide what can be eaten and what cannot be eaten. If you lived in the Mediterranean, for instance, you would consider octopus a great delicacy. You woul...