(1) SO₃ + H₂O -> H₂SO₄

(2) H₂SO₄ + Na₂SO₃ -> Na₂SO₄ + H₂O + SO₂

(3) SO₂ + H₂O -> H₂SO₃

(4) H₂SO₃ + Na₂O -> Na₂SO₃ + H₂O

1. They started a dancing class last week.

=> A dancing was started last week.

2. Mr.Smith saw the accident

=> The accident was seen by Mr.Smith

3. Somebody has taken my briefcase.

=> My briefcase has been taken.

4. The teacher returned our written work to us

=> Our written work was returned to us by the teacher.

5. She has finished the report by noon.

=> The report has been finished by noon.

6. The mad dog bit the little boy.

=> The little boy was bitten by the mad dog.

7. The police have arrested five suspects.

=> Five suspects have been arrested by the police.

8. The doctor ordered him to take a long rest.

=> He was ordered to take a long rest by the doctor.

9. They started a dancing class last week.

=> A dancing was started last week.

10. Mr. Smith saw the accident

=> The accident was seen by Mr.Smith

11. Somebody has taken my briefcase.

=> My briefcase has been taken.

12. The teacher returned our written work to us.

=> Our written work was returned to us by the teacher.

13. She had finished her report by noon.

=> The report has been finished by noon.

14. The mad dog bit the little boy.

=> The little boy was bitten by the mad dog

15. The police have arrested five suspects.

=> Five suspects have been arrested by the police.

16. The doctor ordered him to take a long rest.

=> He was ordered to take a long rest by the doctor.

17. They are sweeping the streets

=> The streets are being swept.

18. The mailman had already delivered the mail

=> The mail had already been delivered by the mailman.

19. He used to borrow my pen

=> My pen used to be borrowed.

20. You ought to tell him early

=> He ought to be told early.

Có 4 qui tắc:

- Tên khác nhau tương ứng với đại lượng khác nhau.

- Tên không trùng với từ khóa (begin, end, uses, var,...)

- Tên không bắt đầu bằng số.

- Tên không chứa khoảng cách

Cách 1: Nháy đúp vào biểu tượng Microsoft excel trên màn hình (nếu có).

Cách 2: Nhấn nút start, trỏ chuột vào All Program và chọn Microsoft Excel.

Cách 3: Nháy chuột vào biểu tượng Microsoft Excel và nhấn Enter.

Cách 4: Trỏ chuột vào biểu tượng Microsoft Excel, nhấp chuột phải rồi chọn Open.

Trả lời:

Câu 1:

uses crt;

var n,s: integer;

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

begin

clrscr;

write('Nhap n= '); readln(n);

for i:=1 to n do begin

write('nhap so thu ',i,' :'); readln(a[i]);

end;

for i:=1 to n do s:=s+i;

writeln('Tong la: ',s);

readln;

end.

5/7/1885: Tôn Thất Thuyết hạ lệnh tấn công quân Pháp ở tòa Khâm Sứ và Đồn Mang cá.

13/7/1885: Tôn Thất Thuyết nhân danh vua Hàm Nghi ra "Chiếu Cần Vương", kêu gọi văn thân và nhân dân đứng lên giúp vua cứu nước.

Cuộc khởi nghĩa kéo dài nhất trong phong trào chống Pháp cuối thế kỉ XIX đầu thế kỉ XX là gì???

_______ you post this letter for me?

A.Will

B.Do

C.Are

D.Won't