Mark the letter A, B, C or D on your answer sheet to indicate the word that differs from the other three in theposition of the main stress in each of the following questions.

A.intellectual                 

B.accelerate           

C.curriculum          

D.compulsory

Mark the letter A, B, C or D on your answer sheet to indicate the word that differs from the other three in theposition of the main stress in each of the following questions.

A.commitment             

 B.involvement       

C.currency            

 D.economy

Cho phản ứng hóa học sau:

- C H 2 - C H O C O C H 3 - + n N a O H → t - C H 2 - C H O H - + n C H 3 C O O N a

Phản ứng này thuộc loại phản ứng

A. phân cắt mạch polime

B. giữ nguyên mạch polime

C. khâu mạch polime

D. điều chế polime

Trong các phản ứng sau đây: ( 1 )   P o l i   ( m e t y l   m e t a c r y l a t )   +   d u n g   d ị c h   N a O H ; ( 2 )   p o l i   p e p t i t   +   d u n g   d ị c h   K O H ; ( 3 )   n i l o n - 6   +   d u n g   d ị c h   H C l ; ( 4 )   n h ự a   n o v o l a c   +   d u n g   d ị c h   N a O H ; ( 5 )   c a o   s u   B u n a   +   d u n g   d ị c h   b r o m   t r o n g ; ( 6 )   t i n h   b ộ t + d u n g   d ị c h   đ u n   n ó n g ; ( 7 )   x e n l u l o z ơ + d u n g   d ị c h   H C l ; ( 8 )   đ u n   n ó n g   p o l i s t i r e n ; ( 9 )   đ u n   n ó n g   n h ự a   r e z o l   đ ế n   150 0 C ; ( 10 )   l ư u   h ó a   c a o   s u ; ( 11 )   X e n l u l o z ơ   +   d u n g   d ị c h     đ ặ c ,   n ó n g . Có bao nhiêu phản ứng giữ nguyên mạch polime?

A. 4

B. 6

C. 3

D. 5

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 23 to 28.

If you're an environmentalist, plastic is a word you tend to say with a sneer or a snarl. It has become a symbol of our wasteful, throw-away society. But there seems little doubt it is here to stay, and the truth is, of course, that plastic has brought enormous (23)__________, even environmental ones. It’s not really the plastics themselves that are the evil ─ it's the way society chooses to use and (24)__________ them.

Almost all the 50 or so different kinds of modern plastic are made from oil, gas or coal ─ non-renewable natural (25)__________.We (26)__________ well over three million tones of the stuff in Britain each year and, sooner or later, most of it is thrown away. A high (27)__________ of our annual consumption is in the form of packaging, and this (28)__________ about seven percent by weight of our domestic refuse.

Điền vào ô 23

A. savings

B. pleasures 

C. benefits

D. profits

A survey was ______ to study the effects of smoking on young adults.

A. commented

B. filled

C. conducted

D. carried

Polime nào sau đây là polime thiên nhiên?

A. cao su buna

B. amilozo

C. nilon-6, 6

D. cao su isopren

Co : (26-20)+1=7 so

Tong la : (26+20):2x7=161

TBC la :161:7=23 tick nha Vu Nguyen Doan Trang

\(x^2=\frac{5}{7}x\frac{5}{7}=>x=\frac{5}{7}\)