皮皮学，免费搜题
登录
搜题
【单选题】
设样本数据 的均值和方差分别为 和 ，若 为非零常数， ，则 的均值和方差分别为 ( )A.
B.
C.
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】If I had studied hard in the university, I __________ things easy now.
A.
take
B.
would have taken
C.
will take
D.
would be taking
【简答题】销连接主要用于____,既是组合加工和装配时的____零件,有可以作为安全装置中的____。
【单选题】If I they were on sale online, I wouldn' t have bought the traveling bags in thisstore.
A.
know
B.
knew
C.
had known
D.
have known
【单选题】“ If I were you, I wouldn ’ t wait to propose to her. ” The subjunctive mood in the sentence is used to _____.
A.
alleviate hostility
B.
express unfavorable feelings
C.
indicate uncertainty
D.
make a suggestion
【单选题】Woman: I'd like really to go to the concert tonight, but I don't know if I can spare the time. Man: Music always relaxes me. It might be worth it in the long run. Question: What does the man suggest t...
A.
Check her calendar.
B.
Go to the concert with the man.
C.
Get some exercise.
D.
Attend the performance.
【单选题】If I cheat in the examination, do you think I might ______ it? [ ]
A.
get away with
B.
look forward to
C.
watch out for
D.
catch sight of
【简答题】销连接主要用于 ,既是组合加工和装配时的 零件, 又可以作为安全装置中的 。
相关题目：