问题
辨音题
| Choose the different pronunciation of the underlined letters. 选择单词中划线字母发音不同的—个。 |
| ( ) 1. A. room ( ) 2. A. live ( ) 3. A. great ( ) 4. A. what ( ) 5. A. sing ( ) 6. A. buses ( ) 7. A. pencils ( ) 8. A. south ( ) 9. A. cold ( ) l0. A. never | B. book B. nice B. bread B. how B. ring B. dishes B. stamps B. cousin B. no B. he | C. boot C. his C. meet C. his C. fine C. dresses C. maps C. how C. open C. help | D. school D. is D. see D. he D. sink D. clothes D. caps D. now D. hot D. men |
答案
1-5: B B B A C 6-10: D A B D B
(λ为波长)，设两波在S1、S2连线上传播时，它们的振幅都是A，且不随距离变化，已知在该直线上在S1，左侧各点的合成波的强度为其中一个波强度的4倍，则两波源应满足的相位条件是()。