Cho dãy các chất: Phenyl axetat, anlyl axetat, metyl axetat, etyl fomat, tripanmitin. Số chất trong dãy khi thủy phân trong dung dịch NaOH (dư), đun nóng sinh ra ancol là :

A. 4

B. 5

C. 2

D. 3

a=2,5,8; b=2

a=1,4,7 ; b=6

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 45 to 54.

When most people hear the term “National Park”, they automatically think of names
such as “Yellowstone”, or “Yosemite”, or “Grand Canyon”. The big parks’ names bring to mind vast stretches of undisturbed wilderness perfect for hiking, camping, and naturewatching. But while this vision of America’s National Parks is wholly accurate and sufficiently
breathtaking, there’s more.

America’s National Park system has an incredible 388 places to visit. This number includes not only the big parks, but also monuments, historical sites, recreation areas, battlefields, as well as scenic lakeshores, seashores, and rivers. And the Parks themselves don’t just stop at geyser-fields and mule-excursions. In America’s National Parks, you can climb an active volcano in Hawaii, “spelunk” the vast underground world of Mammoth Cave in Kentucky, dive the exotic coral reef of Biscayne Bay in Florida, or cast your fishing nets in the far reaches of the Pacific with the locals of American Samoa. Each of these 388 places has a unique appeal- from the natural to the manmade, from the ethereal to the factual, from the subtle to the overwhelming – with the whole collection offering vacationers a nearly endless range of interests and activities in which to explore and indulge.

SeeAmerica.org is a great place to begin planning your trip to one of, or several of, America’s National Parks. From the homepage, you can search all of the parks by name, region, activity, or even zip code. The site also serves as a portal to other important sites, like the National Park Service’s official website, www.nps.gov, and the National Park Foundation’s, www.nationalparks.org. From SeeAmerica.org, you can get to all the
information you’ll need to plan your trip from start to finish – from directions to the park, to park fees, to typical weather conditions.

Which of the following statements is NOT true?

A. The names of the parks just suggest part of the pleasure of visits to them. 

B. There are 388 places of interest in the US national park system. 

C. All you see at national parks are natural. 

D. There are a great variety of things for vacationers to enjoy.

Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.

Who was the last one ______the classroom yesterday?

A. to leave

B. left

C. leaving

D. had left

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

In the history of technology, computers and calculators were innovative developments. They are essentially different from all other machines because they have a memory. This memory stores instructions and information. In a calculator, the instructions are the various functions of arithmetic, which are permanently remembered by the machine and cannot be altered or added to. The information consists of the numbers keyed in.

An electronic pocket calculator can perform almost instant arithmetic. A calculator requires an input unit to feed in numbers, a processing unit to make the calculation, a memory unit, and an output unit to display the result. The calculator is powered by a small battery or by a panel of solar cells. Inside is a microchip that contains the memory and processing units and also controls the input unit, which is the keyboard, and the output unit, which is the display.

The input unit has keys for numbers and operations. Beneath the key is a printed circuit board containing a set of contacts for each key. Pressing a key closes the contacts and sends a signal along a pair of lines in the circuit board to the processing unit, in which the binary code for that key is stored in the memory. The processing unit also sends the code to the display. Each key is connected by a different pair of lines to the processing unit, which repeatedly checks the lines to find out when a pair is linked by a key.

The memory unit stores the arithmetic instructions for the processing unit and holds the temporary results that occur during calculation. Storage cells in the memory unit hold the binary codes for the keys that have been pressed. The number codes, together with the operation code for the plus key, are held in temporary cells until the processing unit requires them.
When the equals key is pressed, it sends a signal to the processing unit. This takes the operation code-for example, addition-and the two numbers being held in the memory unit and performs the operation on the two numbers. A full adder does the addition, and the result goes to the decoder in the calculator's microchip. This code is then sent to the liquid crystal display unit, which shows the result, or output, of the calculation.

What is the main purpose of the passage?

A. To discuss innovative developments in technology

B. To compare computers and calculators with other machines

C. To summarize the history of technology

D. To explain how a calculator works

Mcd

các tập hợp con là;

1 2;1 3;1 4;2 3;2 4;3 4

vậy có tất cả 6 tập hợp con

Cho các loại hợp chất: aminoaxit (X), muối amoni của axit cacboxylic (Y), amin (Z), este của aminoaxit (T), dãy gồm các hợp chất đều phản ứng với NaOH và dung dịch HCl là:

A. X, Y, Z, T

B. X, Y, T

C. X, Y, Z

D. Y, Z, T