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【简答题】
负反馈放大电路引起自激振荡的根本原因是电路在高频或低频区产生了足够大的( ),使负反馈变成了正反馈。
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反馈参考答案：
举一反三
【多选题】下列有关标准离差说法正确的是( )
A.
在期望值相同的情况下，标准差越大，风险程度也越大
B.
标准差只适用于期望值相同的决策方案的风险程度比较
C.
标准差率是标准差对期望值的比例
D.
标准差反映不同风险条件下的预期收益与期望值之间的相差程度
【单选题】Talks and Conversations Directions: In this part of the test, you will hear several short talks and conversations. After each of these, you will hear a few questions. Listen carefully because you will...
A.
They bought some worthless souvenir.
B.
They did some manual work.
C.
They went on a company trip.
D.
They wrote a guidebook.
【单选题】Talks and Conversations Directions: In this part of the test, you will hear several short talks and conversations. After each of these, you will hear a few questions. Listen carefully because you will...
A.
He is out of work now.
B.
He is worried about unemployment.
C.
He is planning on next year.
D.
He is thinking of further education.
【单选题】Part C. Directions : You will hear three dialogues or monologues. Before listening to each one ,you w/// have 5 sec-onds to read each of the questions which accompany /t. While listening ,answer each ...
B.
,
C.
or
D.
. After listening ,you will have 10 seconds to check your answer to each question. You will hear each piece once only. Questions 11-13 are based on the following talk about prodigies, kids with unusual natural a-bilities. You now have /5 seconds to read Questions 11-13. 11. What was John Stewart Mill? [A] A historian. [B] A composer. [C] A philosopher. [D] A mathematician.
【单选题】Talks and Conversations Directions: In this part of the test, you will hear several short talks and conversations. After each of these, you will hear a few questions. Listen carefully because you will...
A.
Dentist and patient.
B.
Surgeon and patient.
C.
Physician and patient.
D.
Pharmacist and patient.
【单选题】Talks and Conversations Directions: In this part of the test, you will hear several short talks and conversations. After each of these, you will hear a few questions. Listen carefully because you will...
A.
The products were all made from fresh vegetables and fruits.
B.
The homemade products were actually made in the factory.
C.
The factory was equipped with the most sophisticated machinery.
D.
There were homemade fresh vegetables and fruits in the factory.
【单选题】Talks and Conversations Directions: In this part of the test, you will hear several short talks and conversations. After each of these, you will hear a few questions. Listen carefully because you will...
A.
Gym and sunbed.
B.
Fitness class.
C.
Weight-lifting exercise.
D.
Whole food bar.
【简答题】Part One Choose the right picture according to what you hear.
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