1. What time
2. How
3. How old
4. When

B1
2. C
3. C
4. A
B2
2. 5 more; 1
3. 4; 2 than
4. 1; 3 pupil
5. 3; 4

a) x= 3² . 5 = 9 . 5 = 45
Ư(45) = \(\left\{-1;1;-3;3;-5;5;-9;9;-15;15;-45;45\right\}\)

x có 12 ước
b) y= 2² . 3 . 5 = 60
Ư(60) = \(\left\{-1;1;-2;2;-3;3;-4;4;-5;5;-6;6;-10;10;-12;12;-15;15;-20;20;-30;30;-60;60\right\}\)

y có 24 ước

BT1
1.
(-) We aren't working in the new show right now
(?) Are we working in the show right now?
2.
(+) I'm talking on the phone at the moment
(?) Are you talking the phone at the moment?
3.
(+) He is runing very fast
(-) He isn't runing very fast
4.
(-) Julia isn't baking a chocolate cake at the moment
(?) Is Julia baking a chocolate cake at the moment ?
5.
(+) Tony and Kaity are helping teacher right now
(-) Tony and Kaity aren't helping teacher right now

BT2
1. The birds are singing at 5 am.
2. Big dogs are barking at 7 am
3. Mrs Thompson is getting up at 7.20 am
4. She is making her son's breakfast at 7.40
5. The mailman is delivering the letters at 7.50
6. Mrs Thompson is washing his face at 7.55
7. Thompson's family are eating breakfast together at 8 am
8. Câu này đề cứ lạ lạ =(
9. My classmate is skipping the rope in the play ground
10. My sister is studying in an International school