Hãy dùng từ gợi ý viết hoàn chỉnh những câu sau:

1. You / know / who invent / ballpoint pen ?

do you know who invented the ballpoint pen ?

2. When / I / primary school / teacher / make / me / write / fountain-pen.

when i was in primary school, the teacher made me write with fountain-pen

3. At / time / I / prefer / use / ballpoint pen.

at that time, i prefered to use ballpoint pen

4. Ballpoint pens / use / to / very expensive / when / first introduce / Viet Nam.

Ballpoint pens used to be ver expensive when they were first introduced into Vietname

5. Father / say / ballpoint pen / used / cost / some VND.

my father said that a ball point pen used to cost some VND

6. Big / French company / make / ballpoint pens / call / Bic.

the big French company which makes ballpoint pens is called Bic

7. How many / ballpoint pens / produce / world / each year?

how many ballpoint pens are introduced in the world each year?

8. Ballpoint pens / use / widely / than / fountainpens.

Ballpoint pens are used more widely than fountainpens.

9. It / because / they / cheaper / and / convenient.

it's because they are cheaper and more convenient

10. It / advisable / that / children / learn / write / not use / ballpoint pens.

it is advisable that children who are learning to write shouldn't use ballpoint pens.

Giải TV nè:
Ta có: 2 bút+3 tẩy=60000đ (A)
3 bút+1 thước=75000đ (B)
Gấp các gt ở B lên 2 lần, gấp các gt ở A lên 3 lần, ta có:
6 bút+9 tẩy=180000đ (C)
6 bút+2 thước=150000đ (D)
Lấy C-D, ta có: 9 tẩy-2 thước=30000đ (E)

Vì 1 thước đắt hơn 1 tẩy 3 lần
=> 1 thước=3 tẩy (thay vào E), ta có

9 tẩy-6 tẩy=30000đ
3 tẩy=30000đ

1 tẩy=10000đ

=> 1 bút=15000đ
1 thước=30000đ

bạn viết sai, phải là "eraser"

sao kho vay. I don"t english

Let the number of pens at first be x.

The number of pens that the group of 9 students took is: 9 x 7 = 63

The number of pens left: x - 63 = 6 => x = 69

Thus, at first there were 69 pens.

Let the number of pens at first be x.

The number of pens that the group of 9 students took is: 9 x 7 = 63

The number of pens left: x - 63 = 6 => x = 69

Thus, at first there were 69 pens

These sre pens needed :

24:8=3(pens)

Sorry Le Minh !!^^

The pens needed was: 24:8=3pens

24:8=3. There are three pens are needed.

Trump pay 389$. Make friend with me!

1. Doesn't -> Don't

2. I have some pen -> pens

3. Many -> much 

4. is famous -> is the most famous of beatiful places

5. is -> are

1. will have

2. was made

3. was waiting

4. to repair

5. wasn't

4-repair

Đề tự dịch: Mười hai cây bút giá 24,6 đô-la. Hỏi giá của một một cây bút là bao nhiêu?

Vậy giá 1 cây bút là

     24,6 : 12 = 2,05 đô-la

A dozen pens = 1 tá bút mực = 12 cái bút mực

=> 12 cái bút mực có giá 24.6 dollars.

Vậy một cái bút có giá là: 24.6 : 12 = 2.05 dollars.

hay day