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. Fill in the appropriate word in question 35

            Our family has got many books. All the …(33)……… of our family buy books and read them. My mother says that books help us in self-education. In ancient times, books ……(34)…… written by hand. It was difficult to write a book …(35)……… a pen. Then printing came into our life. Printing played an important ……(36)…. in the development of literature and culture. Now there are a lot of books in the shops, there are many books in our flats. But it is difficult to buy all books …(37)……… we want to read. That’s why we get books in public libraries. There are some problems in our life and sometimes it is difficult to ……(38)… them. I think that books can help us. Last year I read a very interesting book “ An American Tragedy” by Theodore Dreiser.

            This novel was …(39)…… at the beginning of the 20^th century. The novel ……(40)……. The tragic fate of a boy and a girl, Clyde and Roberta ……(41)…… name. It is a sad story. This novel was written many years ago, but it is …(42)……… nowadays. Books must be our friends during our life.

A. in

B. by

C. with

D. at

Hòa tan 7,8 gam hỗn hợp gồm Al và Mg trong 1,0 lít dung dịch HNO₃ 1M thu được dung dịch B và 1,792 lít hỗn hợp hai khí N₂ và N₂O (đktc) có tỉ khối so với H₂ là 18. Cho vào dung dịch B một lượng dung dịch NaOH 1M đến khi lượng kết tủa không thay đổi nữa thì cần 1,03 lít. Khối lượng muối thu được trong dung dịch B là

A. 52,44 gam

B. 50,24 gam

C. 57,40 gam.

D. 58,20 gam.