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Tham Khảo

Here are some of my tips for learning English well. For me, the best way has always been watching films, cartoons, TV shows and certain TV channels like BBC or Sky news. When I was little, I watched Cartoon Network and despite I didn't understood a word, I kept watching and now I see that it was a good thing to do. The second good way to learn English is writing several times the new words we learn, for instance, when I learned the colours or the numbers or even the name of our clothes, the homework was to write each new word five or ten times! This definitely helped me a lot! The next advice is to read more, not only books but newspapers and magazines as well! There is so much good and new vocabulary in a book that we have no idea! That's why I try to read in English at every opportunity that I have!

Tham Khảo

There is an electronic device that is very familiar and appears in every house. It is hard to find a place without its presence, and it is the TV. After inventors successfully simulated it in the 1920 s, television had become one of the must - have items of every family. Television is an excellent entertaining device, and it is not easy to be replaced by any other things. When we talk about entertaining forms, there are not many things that are as interesting as a TV. Nowadays, there are thousand TV stations all over the world that provide countless channels with competitive contents. When we sit in front of a TV with a remote in our hands, we can easily access to the world through many different lens. The news becomes so lively, the celebrities becomes so close, and the information becomes so easy to be remembered. TV can not only entertain ourselves, but it can also cheer up a whole family or a team. How great is it when we can sit together to watch our favorite TV shows after a long day outside, and we can even talk about them for the next few days. Maybe we do not realize, but TV actually has some positive impacts on us. Unlike the Internet with a huge number of contents which are not censored and confirmed, most of the things that displayed on TV are already checked. We do not have to worry much about absorbing wrong sources of information or harmful content when watching TV, and all we need to do is choosing the property programs which suits our age and hobby. TV plays a big role in our daily life, and the world would be a very boring place without it.

Trường hợp 1: m=0

=>Phương trình sẽ là -3=0(vô lý)

Trường hợp 2: m<>0

Do đó: Phương trình luôn có hai nghiệm phân biệt

Vậy Phương trình có hai nghiệm hai nghiệm phân biệt khi m<>0

uses crt;

var a:array[1..100]of integer;

i,n,t,tam,j:integer;

begin

clrscr;

readln(n);

for i:=1 to n do readln(a[i]);

for i:=1 to n-1 do 

  for j:=i+1 to n do 

if a[i]<a[j] then

begin

tam:=a[i];

a[i]:=a[j];

a[j]:=tam;

end;

for i:=1 to n do write(a[i]:4);

writeln;

t:=0;

for i:=1 to n do 

 if a[i] mod 2=0 then t:=t+a[i];

writeln(t);

readln;

end.

program giaitin_hoc24;

uses crt ;

var a,n : real;

A:real;

begin

clrscr;

write(' a,n : ');

readln(a,n);

A:=A+ axp(n) ;

write('A= ', A:6:2);

readln

end.

Xét tam giác MNO và tam giác HNO có :
NO : chung
MN = NH ( GT )
góc MNO = góc ONH ( do NO là phân giác góc MNP )
=> tam giác MNO = tam giác HNO ( cgc )
=> góc NMO = góc OHN ( cặp góc tương ứng )
mà góc NMO = 90 độ ( GT )
=> góc OHN = 90 độ
=> OH vuông góc NP
Vậy....
Câu b)
Do tam giác MNO = tam giác HNO ( CM ở câu a )
=> MO = OH
Xét tam giác MOK và tam giác HOP có :
góc OMK = góc OHP ( = 90 độ )
MO = HO ( CMT )
góc MOK = góc HOP ( 2 góc đối đỉnh )
=> tam giác MOK = tam giác HOP ( gcg )
=> OK = OP

Câu c)
Do tam giác MNO = tam giác HNO ( CM ở câu a)
=> góc NOM = góc NOH ( cặp góc tương ứng ) 
Mà góc NOM = góc IOP ( 2 góc đối đỉnh ) 
và  góc NOH = góc KOI ( 2 góc đối đỉnh ) 
=> góc KOI = góc POI 
Xét tam giác KOI và tam giác POI có :
OK =PO ( CM ở câu b )
OI : chung
góc KOI = góc POI ( CMT )
=> tam giác KOI = tam giác POI ( cgc )
=> KI = IP 
=> I là trung điểm KP 
Ta có : NM = NH ( GT )
Mà MK = HP ( do tam giác MOK = tam giác HOP )
=> MN + MK = HN + HP 
=> NK = NP 
=> tam giác NKP cân tại N
=> góc NKP = ( 180 độ - góc KNP )/2 
CMTT : góc NMH = ( 180 độ - góc MNH )/2 
Hay góc NMH = ( 180 độ - góc KNP )/2 
=> góc NKP = góc NMH 
Mà 2 góc ở vị trí đồng vị
=> MH // PK 

Câu a)
Xét tam giác MNO và tam giác HNO có :
NO : chung
MN = NH ( GT )
góc MNO = góc ONH ( do NO là phân giác góc MNP )
=> tam giác MNO = tam giác HNO ( cgc )
=> góc NMO = góc OHN ( cặp góc tương ứng )
mà góc NMO = 90 độ ( GT )
=> góc OHN = 90 độ
=> OH vuông góc NP
Vậy....
Câu b)
Do tam giác MNO = tam giác HNO ( CM ở câu a )
=> MO = OH
Xét tam giác MOK và tam giác HOP có :
góc OMK = góc OHP ( = 90 độ )
MO = HO ( CMT )
góc MOK = góc HOP ( 2 góc đối đỉnh )
=> tam giác MOK = tam giác HOP ( gcg )
=> OK = OP

35. If you have fever, cough and difficulty breathing, seek medical care early.

36. You can prevent viruses from entering your body by washing your hands often and properly.

37. Since they haven't replied my invitation, I think that they're not coming to my party.

38. He doesn't study English well enough to be an intepreter.

39. I was disappointed that the quality of the wine was bad.

40. If we don't set off early, we'll get stuck in traffic.