Trong các phép biến hình có được bằng cách thực hiện liên tiếp hai phép biến hình sau đây, phép không là phép dời hình :
A. Phép đối xứng trục và phép đối xứng tâm.
B. Phép đối xứng tâm và phép vị tự tỉ số k = −1.
C. Phép quay và phép chiếu vuông góc lên một đường thẳng
D. Phép quay và phép tịnh tiến

Choose the best answer for the following sentence:
If I ____________, I’ll let you know. 
A. am staying              
B. will stay             
C. do stay                
D. would stay

Choose the best answer for the following sentence:
He was acquitted __________ the crime.
A. into                 
B. of                   
C. upon                  
D. over

Choose the best answer for the following sentence:
This baby ________ walk in a few weeks. 
A. will be able to
B. can           
C. will can 
D. need

Choose the best answer for the following sentence:
________ she was watering the flowers, it began to rain.
A. While
B. Since
C. Because
D. For

Choose the best answer for the following sentence:
We just rested ___________ a short time. 
A. at               
B. since                 
C. for                
D. in

Choose the best answer for the following sentence:
ESL students from Asia often have great difficulty __________________ some English sounds. 
A. to pronounce               
B.  in pronouncing 
C. pronouncing                
D. B and C are correct

Choose the best answer for the following sentence:
Levin hardly had time to think when, moving more and more rapidly, the oak tree vanished behind the other trees, and he heard the ______________ of the great tree falling upon the others. 
A. strike             
B. collision                
C. crash                   
D. accident

Choose the best answer for the following sentence:
I just want to know what you __________________ at this time tomorrow afternoon. 
A. are going to do             
B. will be doing 
C. are doing               
D. do

Choose the best answer for the following sentence:
One member did not concur ___________ others.
A. about
B. with
C. on
D. over