皮皮学，免费搜题
登录
搜题
【单选题】
频率为100Hz，传播速度为300m／s的平面简谐波，波线上两点振动的相位差为 ,则此两点相距为( )m。A.
2
B.
2.19
C.
0.5
D.
28.6
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【单选题】关于慢性阻塞性肺疾病（COPD），下列不正确的是（）
A.
COPD是一种气流受限为特征的肺部疾病，气流受限完全不可逆
B.
COPD最重要的危险因素是吸烟
C.
多种细胞参与COPD的气道炎症，其中中性粒细胞是主要的效应细胞
D.
COPD的病理改变主要表现为慢性支气管炎及肺气肿的病理变化
E.
早期COPD患者第一秒用力呼气容积（FEV）、最大通气量、最大呼吸中气流速多为正常
【单选题】You didn’t take his advice. ____ his advice, you _____ such a mistake.
A.
Had you taken; wouldn’t have made
B.
If you had taken; would make
C.
Were you to take; shouldn’t have made
D.
Have you taken; won’t have made
【单选题】You lent him $10,000 yesterday? You must ________ by him!
A.
be taken in
B.
have taken in
C.
take in
D.
have been taken in
【单选题】Have you prepared for the sports meeting which ______ soon?
A.
has taken place
B.
will be taken place
C.
is to take place D is to be taken place
【单选题】You the day off from work, which created a burden for everyone else.
A.
shouldn’t have taken
B.
mustn’t have taken
C.
couldn’t have taken
D.
wouldn’t have taken
【单选题】－Bob, have you packed yet? －Yes, Mum. －Look over and that you have taken everything you need.
A.
look for
B.
make sure
C.
find out
D.
work out
【单选题】Have you prepared for the sports meeting which _____ soon?
A.
has taken place
B.
will be taken place
C.
is to take place
D.
is to be taken place
相关题目：
参考解析：
知识点：
题目纠错 0
发布
