\(\dfrac{9}{27}\)=\(\dfrac{9:9}{27:9}\)=\(\dfrac{1}{3}\) ; \(\dfrac{15}{20}\)=\(\dfrac{15:5}{20:5}\)=\(\dfrac{3}{4}\)

Vậy \(\dfrac{1}{3}\)+\(\dfrac{3}{4}\)=\(\dfrac{4}{12}\)+\(\dfrac{9}{12}\)=\(\dfrac{13}{12}\)

Ta có: \(\dfrac{21}{35}\)=\(\dfrac{21:7}{35:7}\)=\(\dfrac{3}{5}\)

Vậy \(\dfrac{3}{5}\)+\(\dfrac{5}{4}\)=\(\dfrac{12}{20}\)+\(\dfrac{25}{20}\)=\(\dfrac{37}{20}\)

giúp mình ạ

Ex2. Rewrite each sentence, beginning as shown, so that the meaning stays the same.

1. My daughter started learning the piano a month ago.

My daughter has ​.

2. When he heard the results of the entrance exam, Nam began to feel more confident.

Since hearing the result ​.

3. This is my first visit to New Zealand.

This is the first time... 

4. The last time Tom played basketball was in 2016.

Tom hasn't ​

5. How long has your family moved to Singapore?

When ​------?

6. It's a long time since my last conference participation.

I ​...

7. My sister hasn't taken an IELTS exam for ages.

It's ages ​

8. This is her first presentation in front of the whole class.

She ​

9. Hoa didn't wear near-sighted glasses until recently.

Hoa has only ​

10. Mr Lam started doing his PhD two years ago.

Mr Lam has

giúp mình với ạ

Ex1. Find the mistake in each sentence and correct it. The first one has been done for you.

1. When has this training course started?

→ When did this training course start?

2. Your mother has ever been studying abroad before?

3. How long the orientation and training programs has lasted?

4. The training session is over and the trainees have been returning to their jobs to begin applying what they've learned.

5. My younger brother has been knowing Thomas Edison since he was a child.

6. My family and I went to the same holiday resort every year since 2011.

7. Have you been decided which country to go for a higher education?

8. Lan is tired because she has worked on her project for the whole day now.

9. My parents are not at home. They travelled since last September.

10. They have just been finishing filming a TV series called Jungle.

11. What did they enjoy since their return to their home country?

Giúp mình với ạ

Ex2. Complete the sentences, using the correct form of the words in brackets.

1. Requirements for admission to high-level graduate programs is extremely……………and admitted students are expected to perform well. (COMPETE)

2. The Government is committed to ensuring that all education authorities operate effective systems of staff……………and review. (DEVELOP)

3. Online……………education has made it easier than ever for students to learn various trade skills and soft skills from established professionals in the industry. (VOCATION)

4. ……………….. to university in Vietnam is determined through the National High School Graduation Examination, whose results will be considered for evaluation. (ENTER)

5. In America, among undergraduate fields of study, science, technology, engineering, math, and business generally offer the highest wages and best chances of…………… (EMPLOY)

6. According to Communicative Language Teaching approach, the goal of language education is the ……………….. to communicate in the target language. (ABLE)

7. Vocational training programs generally focus on​……………….. students with hands-on instruction, and can lead to certification, a diploma or certificate. (PROVIDE)

8. Their college has an excellent reputation in ……………….. results and vocational education. (ACADEMY)

9. A lecture is an oral presentation intended to present……………or teach people about a particular subject. (INFORM)

10. The admission to a postgraduate program at an Argentine University requires the full ……………….. of any undergraduate course. (COMPLETE)

Giai giúp mình với ạ

Exercise 1. You may have to change the form of the words.

scholarship

internship

doctorate

qualification

postgraduate

academic

professional

subject

vocational

critical thinking

1. If you want a…………..career, you will need to go to university and get a degree.

2. Their school offers a wide range of……………in the humanities and sciences.

3. It is essential to regard……………training as a part of a youngster's education.

4. At the age of eighteen, he gained a mathematical……………at Trinity College, Cambridge.

5. To become a teacher of that famous high school, he has been required to show a number of ………………..

6. The student desiring to proceed to the ……………….. is free from examinations thereafter until he presents his thesis for the doctor's degree.

7. We need……………to evaluate and improve our creative ideas.

8. She had a long……………before starting her career as a general practitioner.

9. Most of the lecturers in the faculty hold……………degrees.

10. She has been offered a teaching job and decided to return to……………life.

1.  Cell phones are not allowed on Tokyo subway. (must)

->Passengers                                                                                                                             

2.  Doing physical activities is necessary for children (need)

->Children                                                                                                                                                   3.  Jenny advised Timmy to leave his home at 12:30 pm to catch the 1:00 pm train, (should) ->Jenny said to Timmy:

Trong các trường hợp sau, trường hợp nào dẫn điện? Xác định chất điện li?

1. K2O nóng chảy.

2. Cho Na và H2O được dung dịch

3. CO2 vào nước

4. Đơn chất kim loại :Cu, Al

5. KCl nóng chảy