Trong dao động điều hòa của con lắc lò xo, lực phục hồi tác dụng lên vật:
A.Tỉ lệ nghịch với khoảng cách từ vật đến vị trí cân bằng và hướng ra xa vị trí cân bằng
B.Tỉ lệ với độ biến dạng của lò xo
C.Tỉ lệ với khoảng cách từ vật đến vị trí cân bằng và luôn hướng về vị trí cân bằng
D.Có giá trị không đổi

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
I want to work as an interpreter in the future________ I am studying Russian at university.
 
A.so
B.therefore
C.however
D.but

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
This is _______ that it took me much time to finish it.
 
A.but not enough difficult homework
B.so difficult homework
C.such difficult homework
D.however difficult homework

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
_______ the firemen arrived to help, we had already put out the fire.
 
A.No sooner
B.By the time
C.Until
D.After

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
_____ hard he worked, he couldn’t earn enough money to support the family.
 
A.But
B.Whatever
C.However
D.Therefore

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
We are having trouble with staff changing shifts . Does anybody come ______ with any better ideas?
A.up
B.along
C.into
D.for

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
They cancelled the match _______ .
 
A.because of the heavy rain
B.because of it rained heavily
C.because the heavy rain
D.due to it rained heavily

 
Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
_______, Peter came to see me.
 
A.When lam having dinner
B.While having dinner
C.While I was having dinner
D.When having dinner

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
1. When it’s come to examinations, if you don’t work hard, you will not keep up _____ your friends.
A.for
B.on
C.of
D.with

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to the following question.
Anna needed some money, ________, she took a part-time job.
 
A.furthermore
B.however
C.therefore
D.moreover