\(a.\\ Z=11\\ 1s^22s^22p^63s^1\)

Là nguyên tố kim loại do số e của lớp ngoài cùng bằng 1

\(b.\\ Z=29\\ 1s^22s^22p^63s^23p^63d^{10}4s^1\)

Là nguyên tố kim loại do số e của lớp ngoài cùng bằng 1

1. The last time I played the violin was 2 years ago

=> I haven't played the violin for 2 years.

2. The last time the team won the prize was a long time ago.

=> The team hasn't won the prize for a long time.

3. She last did charity work 2 years ago.

=> She hasn't done charity work for 2 years

4. The last time I wrote a letter was 5 years ago.

=>I haven't written a letter for 5 years

5. My father stopped smoking in 2014.

=>My father hasn't smoked since 2014

6. I last donated my blood 7 months ago.

=>I haven't donated my blood for 7 months

7. When did you start doing charitable work? 

=>How long have you done charitable work?

8. The last time she involed in sommunity service was 2 months ago.

=> She hasn't involed in sommunity service for 2 months .

9. She said: "I began working as an activist when I was 20 years old."

=> She said she had begun working as an activist since she was 20 years old

10. My best friend gave up eating fast food last year.

=> My best friend has given up eating fast food for 1 year

1. If I were you, I would take more exercises

2. At no time did he suspect that the money had been stolen.

3. Have you ever ridden a horse ?

4. Mình không chộ đề bài nơi ...

1. I think I've heard that song before

2.They haven't come yet

3.Jim has already invited Shirley to his party.

4.John and Julie have had their house for about two years.

5.She hasn’t taken her driving test yet.

6.Mary has been a translator since she left university.

7.Have you ridden your new car yet?

8.Has Paul ever met a famous person?

9.Up to now, Peter has received 5 awards.

1. will be stopped

2. hadn't given

3. to switch off

3. would have gone out

1. g

2. d

3. f

4.b

5. a

6.c

7.e

Câu 17

Because it can make your cough less, make you feel better, and stop your nose running for a while

Câu 18

People drink a lot of hot water with sugar, lemon juice

Because it helps provide them with a lot of vitamin

Câu 23

Because it rained heavily, he couldn't go to school

Câu 24

B

Câu 25

A

1.A

2.D

3.B

4.C

5.A

\(\dfrac{x+1}{3}=\dfrac{y+2}{4}=\dfrac{z+3}{5}\\ =\dfrac{x+1+y+2+z+3}{3+4+5}=\dfrac{24}{12}=2\)

Từ:

\(\dfrac{x+1}{3}=2\\ =>x+1=6\\ < =>x=5\)

\(\dfrac{y+2}{4}=2\\ =>y+2=8\\ < =>y=6\)

\(z=18-x-y=18-5-6=7\)