dung dịch X gồm 2 axit: HCl 0.001M và CH₃COOH 0.1M

a) Tính pH của dung dịch X. biết axit CH₃COOH có K_a= 1,8.10^-5

b) Hòa tan 2,04g NaOH vào 1 lít dung dịch X thu được dung dịch Y. Tính pH của dung dịch Y

giúp khẩn cấp với các đồng chí ơi

Read the following pasage and mark the letter A. B, C or D on your answer sheet to indicate the correct answer to each of the questions from 34 to 40.

As computers have become powerful tools for rapid and economic of production of picture, computer graphics has emerged as one of the most rapidly growing fields in computers scienee. It such used routinely in such diverse areas as business, industry, government, research, training, and madiecine.

One of of the initial uses of computer graphics and ultimately its greatest use, been as an aid to design, generally referred to as computer – aided degign (CAD). One of its greatest advantages is that designers can see how an object will lock after construction and make changes freely and much more quickly than with hands drafting. For three-dimensional rendering of machine parts, engineers rely heavily on CAD. Automobile, spacecraft, aerospace, and ship designers use CAD terluaiques to design vehicles and test their pertomance. Building designs are also created with computer graphics systems. Architect can design a building layout create a three-dimersional model, and even go for simulated “walk” through the rooms or around the outside of the building.

Business graphics is another rapidly growing are of computer graphics, where it is to create graphs, charts, and cost models summarize financial, statistical, msthematieal, scientific, and economic data. As an education aid, computer also has creative and commencial art applications, where it is used in advertissing, publishing and film productions, particulurly for computer animation, which is achieved by a sequential process.

According to the passage, engineers use CAD for ..........................

A. A simulated “walk” through modal rooms

B. Rendering machine parts

C. Making cost models

D. Advertising products

- Cindy: "Would you mind lending me your car?" - Nancy: "______"

A. Yes. Here it is

B. Yes, let's

C. No, not at all

D. Great

The _ of the human body towards the elements and disease is one of the miracles of all time.

A. sensitivity 

B. sensibility 

C. resistance 

D. resilience

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 26 to 30.

School lunch

Research has shown that over half the children in Britain who take their own lunches to school do not eat (26) __________ in the middle of the day. In Britain, schools have to (27) ________ meals at lunchtime. Children can choose to bring their own food or have lunch at the school canteen.

  One shocking finding of the research is that school meals are much healthier than lunches prepared by

parents. There are strict (28) _____________ for the preparation of school meals, which have to include one (29) ___________ of fruit and one of vegetables, as well as meat, a dairy item and starchy food like break or pasta. Lunchboxes examined by researchers contained sweet drinks, crisps and chocolate bars. Children consume twice as much sugar as they should at lunchtime.

          The research will provide a better understanding (30) _____________ why the percentage of overweight in Britain has increased in the last decade. Unfortunately, the government can’t criticize parents, but it can remind them of the nutritional value of milk, fruit and vegetables. Small changes in their children’s diet can affect their future health. Children can easily develop bad eating habits at this age, and parents are the only ones who can prevent it.

Điền vào ô số 28

A. standards

B. procedures 

C. conditions

D. ways 

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions

A. understated

B. washed 

C. produced

D. confessed 

ố biểu diễn số ô vuông của hình trên là

Tìm số tự nhiên a lớn nhất, biết rằng 60 và 504 cùng chia hết cho a

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 36 to 43.

One of the seven wonders of the ancient world, the Great Pyramid of Giza was a monument of wisdom and prophecy built as a tomb for Pharaoh Cheops in 2720 B.C. Despite its antiquity, certain aspects of its construction makes it one of the truly wonders of the world. The thirteen- acre structure near the Nile river is a solid mass of stone blocks covered with limestone. Inside are the number of hidden passageways and the burial chamber of the Pharaoh. It is the largest single structure in the world. The four sides of the pyramid are aligned almost exactly on true north, south, east and west-an incredible engineering feat. The ancient Egyptians were sun worshippers and great astronomers, so computations for the Great Pyramid were based on astronomical observations.

Explorations and detailed examinations of the base of the structure reveal many intersecting lines. Further scientific study indicates that these represent a type of timeline of events - past, present and future. Many of the events have been interpreted and found to coincide with known facts of the past. Others are prophesied for future generations and are currently under investigation. Many believe that pyramids have supernatural powers and this one is no exception. Some researchers even associate it with extraterrestrial beings of ancient past.

Was this superstructure made by ordinary beings, or one built by a race far superior to any known today?

Why is the Great Pyramid of Giza considered one of the seven wonders of the world?

A. It was built by a super race.

B. It is perfectly aligned with the four cardinal points of the compass and contains many prophecies.

C. It was selected of the tomb of Pharaoh Cheops.

D. It was very old.