- Nói mỗi lông hút là một tế bào vì mỗi lông hút đều có những thành phần đặc trưng của 1 tế bào như vách tế bào , màng sinh chất , chất tế bào , nhân , không bào ,.....

- Lông hút không tồn tại mãi , đến một thời gian nào đó nó sẽ rụng và được thay thế bởi một lông hút khác .

cảm ơn Linh nhe!

(the) night is short bn ak.k mk

The  day is long and the NIGHT is short in the summer

''night'' nha

d.take nha

tik mk nè

Let's ........ a look at the film section of the paper.

A. do     B. use     C. spend      D. take

tik nha

D. take

to take a look at:ngắm/nhìn/xem

My dream house will be a one-storey country cottage . Thought many people like to live in a big house , I prefer living in a small one on a farm because I might enjoy fresh air and a peaceful . 

The frond of the house will be made of stone and it will have a nice wooden roof with a chimney on the top . I will use space in my house effciently . There will be a living room , four bedrooms , two bathrooms and large windows that will let in a lot of natural light . 

I love flowers , so I will plant various kinds of flowers around the house . I think it might really lovely . I will take a lot of photos of the flowers every day . This is a hobby . 

Dream nghĩa là giấc mơ , mà giấc mơ nghĩa là mơ về ngôi nhà tương lai sau này . 

LAN SAU BAN HOI MINK SE CAN THAN HON 

Trả lời:

\(\frac{4}{7.9}+\frac{4}{9.11}+...+\frac{4}{107.109}\)

\(=\frac{2.2}{7.9}+\frac{2.2}{9.11}+...+\frac{2.2}{107.109}\)

\(=2.\left(\frac{2}{7.9}+\frac{2}{9.11}+...+\frac{2}{107.109}\right)\)

\(=2.\left(\frac{1}{7}-\frac{1}{9}+\frac{1}{9}-\frac{1}{11}+...+\frac{1}{107}-\frac{1}{109}\right)\)

\(=2.\left(\frac{1}{7}-\frac{1}{109}\right)=2.\frac{102}{763}=\frac{204}{763}\)

Cảm ơn bn Quỳnh Anh nhiều nhé ! 

Bài 1: First task:

Let \(x\) be the number of sparrows on the first lamp post at first. (\(x\) is a positive integer).

\(\Rightarrow16-x\)is the number of sparrows on the second lamp post at first.

We have: \(x-2+3=16-x+2-3\Leftrightarrow2x=14\Leftrightarrow x=7\)

Hence there are 7 sparrows on the first lamp post at first, 9 sparrows on the second lamp post at first.

Bài 2: Second Task

We can find 2 students who were born on the same day.

There are 30 days in April and 31 students were born on that month. Apply the Dirichlet 's theorem, we can ensure that threre exists at least one day where 2 students were born.

\(B=\frac{3^{12}.13+3^{12}.3}{3^{11}.2^{24}}\)

\(B=\frac{3^{12}.\left(13+3\right)}{3^{11}.2^{24}}\)

\(B=\frac{3^{12}.16}{3^{11}.2^{24}}\)

\(B=\frac{3^{12}.2^4}{3^{11}.2^{24}}\)

\(B=\frac{3}{2^{20}}\)

B = 3/2 mũ 20

B=3/2 mũ 20

Hok tốt 

K mink đi 

Her son almost takes after her husband. Sometimes i can't distinguish between them

Mình nghĩ là :

Her son almost takes helps her husband. Sometimes I can't distinguish between them.

mik nghĩ là đề có ván đề vì almosts và takes ko có s mới đúng