\(\left(x+9\right)\left(y+1\right)=12\sqrt{xy}\)

Có bao nhiêu hợp chất hữu cơ mạch hở có công thức phân tử C₃H_xO vừa phản ứng với H₂ ( xúc tác, NI, t⁰c), vừa phản ứng với dung dịch AgNO₃/NH₃ dư, đun nóng 

A. 4

B. 2

C. 5

D. 3

Chia m gam Glucozo thành hai phần bằng nhau:

– Cho phần 1 tác dụng với dung dịch AgNO₃/NH₃ dư, phản ứng xong thu được m1 gam kết tủ a.

– Tiến hành lên men rượu phần 2 với hiệu suất 75% và cho hấp thụ toàn bộ sản phẩm khí thoát ra vào 2 lít dung dịch NaOH 0,5M (D = 1,05g/ml) thu được dung dịch chứa hai muối với tổng nồng độ là 3,21%. Xác định m và m1

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

“The economic history of the United States”, one scholar has written, “is the history of the rise and development of the capitalistic system”. The colonists of the eighteenth century pushed forward what those of the seventeenth century have begun: the expansion and elaboration of an economy born in the great age of capitalist expansion.

Our excellent natural resources paved the way for the development of abundant capital to increase our growth. Capital includes the tools – such as: machines, vehicles, and buildings – that makes the outputs of labor and resources more valuable. But it also includes the funds necessary to buy those tools. If a society had to consume everything it produced just to stay alive, nothing could be put aside to increase future productions. But if a farmer can grow more corn than his family needs to eat, he can use the surplus as seed to increase the next crop, or to feed workers who build tractors. This process of capital accumulation was aided in the American economy by our cultural heritage. Saving played an important role in the European tradition. It contributed to American’s motivation to put something aside today for the tools to buy tomorrow.

The great bulk of the accumulated wealth of America, as distinguished from what was consumed, was derived either directly or indirectly from trade. Though some manufacturing existed, its role in the accumulation of capital was negligible. A merchant class of opulent proportions was already visible in the seaboard cities, its wealth as the obvious consequence of shrewd and resourceful management of the carrying trade. Even the rich planters of tidewater Virginia and the rice coast of South Carolina finally depended for their genteel way of life upon the ships and merchants who sold their tobacco and rice in the markets of Europe. As colonial production rose and trade expanded, a business community emerged in the colonies, linking the provinces by lines of trade and identity of interest.

The phrase “put aside” in the second paragraph is closet in meaning to _____.

A. hidden   

B. saved      

C. reviewed          

D. consumed

Cho hỗn hợp Zn, Cu vào cốc đựng dung dịch AgNO₃, khuấy đều. Sau phản ứng thu được hỗn hợp kim loại X và dung dịch Y. Cho NaOH dư vào dung dịch Y được kết tủa Z. Nung Z đến khối lượng không đổi được rắn T. Nhận định nào dưới đây là đúng?

A. Zn và Cu đều đã phản ứng hết với dung dịch AgNO₃

B. Zn đã phản ứng hết, Cu đã phản ứng một phần với dung dịch AgNO₃

C. Chỉ có Zn phản ứng với dung dịch AgNO₃

D. Chỉ có Cu phản ứng với dung dịch AgNO₃

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

Keeping your distance

Personal space is a term that refers (23) ………. the distance we like to keep between ourselves and other people. When (24) …………. we do not know well gets too close we usually begin to feel uncomfortable. If a business colleague comes closer than 1.2 meters, the most common response is to move (25) ………. Some interesting (26) ……….. have been done in libraries. If strangers come too close, many people get up and leave the building; others use different methods such as turning their back on the intruder. Living in cities has made people develop new skills for dealing with situations where they are very close to strangers. Most people on crowded trains try not to look at strangers; they avoid skin contact, and apologize if hands touch by mistake. People use newspapers (27) …….. a barrier between themselves and other people, and if they do not have one, they stare into the distance, making sure they are not looking into anyone’s eyes.

Điền vào ô trống 23

A. from 

B. about 

C. to 

D. for