Tham khảo

1. Someone will clean the room today. =>THE ROOM WILL BE CLEANED TODAY

2. Someone might steal the car. =>THE CAR MIGHT BE STOLEN

3. They had to cut down that tree.=>THAT TREE HAD TO BE CUT DOWN

4. They're going to demolish the old houses.=>THE OLD HOUSES ARE GOING TO BE DEMOLISHED

5. We can't restore the picture. =>THE PICTURE CAN'T BE RESTORED

6. You must make an appointment in advance.=>AN APPOINTMENT MUST BE MADE IN ADVANCE

7. I don't want people to make me a fool. =>I DON'T WANT TO BE MADE A FOOL

8. Someone has to look after the garden.=>THE GARDEN HAS TO BE LOOKED AFTER

9. He wants everybody to serve him. =>HE WANTS TO BE SERVED

10. They're going to interview him next week=>HE IS GOING TO BE INTERVIEWED NEXT WEEK

Tham khảo

1. Someone will clean the room today. =>THE ROOM WILL BE CLEANED TODAY

2. Someone might steal the car. =>THE CAR MIGHT BE STOLEN

3. They had to cut down that tree.=>THAT TREE HAD TO BE CUT DOWN

4. They're going to demolish the old houses.=>THE OLD HOUSES ARE GOING TO BE DEMOLISHED

5. We can't restore the picture. =>THE PICTURE CAN'T BE RESTORED

6. You must make an appointment in advance.=>AN APPOINTMENT MUST BE MADE IN ADVANCE

7. I don't want people to make me a fool. =>I DON'T WANT TO BE MADE A FOOL

8. Someone has to look after the garden.=>THE GARDEN HAS TO BE LOOKED AFTER

9. He wants everybody to serve him. =>HE WANTS TO BE SERVED

10. They're going to interview him next week=>HE IS GOING TO BE INTERVIEWED NEXT WEEK

ok nha

A = 1/2 + 1/6 + 1/16 + ... + 1/4084441   có : 2021 - 1 + 1 = 2021 số

1 = 1/2021 + 1/2021 + ... + 1/2021   có 2021 số 

vậy 1 > A

a)

Kim loại : $Pb$

Phi kim : $Cl_2,C$

b)

Axit : $CH_3COOH$

Oxit : $Fe_2O_3,CO,N_2O_5$

Bazo : $Ni(OH)_2$

Muối : $KMnO_4,MnSO_4,Na_2HPO_4,NH_4Cl$

\(n_{NaOH}=0.015\cdot2=0.03\left(mol\right)\)

\(n_{H_2SO_4}=0.015\cdot1.5=0.0225\left(mol\right)\)

\(2NaOH+H_2SO_4\rightarrow Na_2SO_4+H_2O\)

\(0.03..........0.015...........0.015\)

\(n_{H_2SO_4\left(dư\right)}=0.0225-0.015=0.0075\left(mol\right)\)

\(C_{M_{Na^+}}=\dfrac{0.015\cdot2}{0.015+0.015}=1\left(M\right)\)

\(C_{M_{H^+}}=\dfrac{0.0075\cdot2}{0.015+0.015}=0.5\left(M\right)\)

\(C_{M_{SO_4^{2-}}}=\dfrac{0.015+0.0075}{0.015+0.015}=0.75\left(M\right)\)

\(\left|cosx\right|=\dfrac{1}{2}\)

\(\Leftrightarrow\left[{}\begin{matrix}cosx=\dfrac{1}{2}\\cosx=-\dfrac{1}{2}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\pm\dfrac{\pi}{3}+k2\pi\\x=\pm\dfrac{\pi}{2}+k2\pi\end{matrix}\right.\)

\(\Leftrightarrow x=\pm\dfrac{\pi}{3}+k2\pi\)

\(\left|cosx\right|=\dfrac{1}{2}\)

\(\Leftrightarrow cos^2x=\dfrac{1}{4}\)

\(\Leftrightarrow\dfrac{1+cos2x}{2}=\dfrac{1}{4}\)

\(\Leftrightarrow cos2x=-\dfrac{1}{2}\)

\(\Rightarrow2x=\pm\dfrac{2\pi}{3}+k2\pi\)

\(\Rightarrow x=\pm\dfrac{\pi}{3}+k\pi\)

Thì là vs nơi ơ, ăn uống hợp vệ sinh, rửa tay trc khi ăn và sau khi đại tiện... nhìu lắm bn ak ;)

- Rửa tay trước khi ăn và sau khi đi vệ sinh .

- Vệ sinh thực phẩm kĩ càng , ăn uống đảm bảo an toà vệ sinh thực phẩm .

- Không nên để móng dài , thường xuyên cát móng chân - tay.

-Tránh tiếp xúc với những nguồn nước bẩn .

- Dọn dẹp , rửa sạch những đồ dùng cá nhân và đồ dùng thông dụng trong gia đình .

- Tránh để trẻ em mút tay hay cắn móng tay .

.......v..........v..........

Chúc bạn học tốt nhé !