Đốt cháy hoàn toàn m gam một este X (có công thức C n H 2 n - 2 O 2 ), thu được V lít CO₂ (đkc) và x gam H₂O. Biểu thức liên hệ giữa m với V, x là

A. m = ( 1 , 25 V - 9 x 7 )

B.  m = ( 2 , 5 V - 7 x 9 )

C.  m = ( 1 , 25 V + 7 x 9 )

D.  m = ( 1 , 25 V - 7 x 9 )

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word for each of the blanks.

Today there are libraries in almost every towns in the world. Even in areas (68)________there are no libraries, there are often mobile libraries which take books from one village to (69)________. But in the days when books were copied by hand (70)________than printed, libraries were very rare. The reason is simple: books took a very long time to produce, and there were far fewer copies of any given work around. The greatest library (71)________all, that in Alexandia had 54,000 books.

In the ancient world, this number (72)________considered huge. It was the first time that anyone had collected so many books from all around the world (73)________one roof. There are many theories about why these books were lost. (74)________is that the library accidentally burned down. Another is that one of the rulers of the city ordered the books to be burned. They were taken to various places and it took six months to burn them. (75)________happened, the collection there was priceless. Many of the library’s treasures were lost forever, some books were never recovered. We cannot even know exactly what the library contained.

Question 70:

A. rather

B. else

C. more

D. much

Đốt cháy 1,85 gam một rượu no đơn chức cần có 3,36 lít O 2 (đktc). Công thức rượu đó là:

A. CH₃OH

B. C₂H₅OH

C. C₃H₇OH

D. C₄H₉OH

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

A. amaze

B. offer

C. release

B. believe

Ý nghĩa của cuộc Chiến tranh nông dân Đức?

khoáng sản là những khoáng vật và đá có ích được con người khai thác, sử dụng