Câu 2

\((1) MnO_2 + 4HCl \to MnCl_2 + Cl_2 + 2H_2O\\ (2) Cl_2 + H_2 \xrightarrow{as} 2HCl\\ (3) 3Cl_2 + 2Fe \xrightarrow{t^o} 2FeCl_3\\ (4) 2FeCl_3 + Fe \to 3FeCl_2\\ (5) 2NaOH + Cl_2 \to NaCl + NaClO + H_2O\)

\((1) 4Al + 3O_2 \xrightarrow{t^o} 2Al_2O_3\\ (2) 2Fe + 3Cl_2 \xrightarrow{t^o} 2FeCl_3\\ (3) C + O_2 \xrightarrow{t^o} CO_2\\ (4) 2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2\\ (5) 4P + 5O_2 \xrightarrow{t^o} 2P_2O_5\\ (6) 2KClO_3 \xrightarrow{t^o} 2KCl + 3O_2\\ (7) Fe + H_2SO_4 \to FeSO_4 + H_2\\ (8) Cu + 2H_2SO_4 \to CuSO_4 + SO_2 + 2H_2O\\ (9) 2Fe + 6H_2SO_4 \to Fe_2(SO_4)_3 + 3SO_2 + 6H_2O\\ (10) 2Al + 6H_2SO_4 \to Al_2(SO_4)_3 + 3SO_2 + 6H_2O\)

1 My sister has learned English for 5 years

2 A supermarket was built near the airport last year

3 I spent three hours cleaning the house yesterday

6 The wall built three weeks ago fell down

7 Unless you leave me alone, I will call the police

8 The suspects are being followed by the police 

10 Nobody in this team is as good at playing football as Tom

Bài 14:

a, 3kv = 3000 V = 3 kv                                c, 0,15 A = 150 mA

b, 12500 mv = 12,5 V                                 d, 1500 mA = 1,5 A

Câu 15)

Theo đề bài ta đc

\(I=I_1+I_2\\ \Leftrightarrow I=I_1+2I_1=1,5\\ \Leftrightarrow\left\{{}\begin{matrix}I_1=1A\\I_2=0,5A\end{matrix}\right.\) 

Câu 14)

\(3kV=3000V\\ 1250mV=1,25V\\ 0,15A=150mA\\ 1500mA=1,5A\)

1 The gymnast won a total of ten medals at 3 Olympic Games

2 The principal invited a sports star to give a talk at my school yesterday

Giúp em với ạ ☺️

c) 1,128

d) 35,217

c)0,24 x 4,7 =1,128

d)7,826 x 4,5 = 35,217