Cho phương trình phản ứng: aFe2O3   + bH2 → cFe + dH2O. Các hệ số cân bằng a, b, c, d là các số nguyên tối giản. Tổng hệ số cân bằng là

A.8

B.9

C.6
D.7

Cho phương trình phản ứng: aKMnO4 + bHCl → cKCl + dMnCl2 + eCl2 + gH2O. Các hệ số cân bằng a, b, c, d, e, g là các số nguyên tối giản. Tổng hệ số (a+b) là

A.17

B.19

C.18

D.26

Cho phương trình phản ứng: aFe + bH2SO4 → cFe2(SO4)3 + dSO2 + eH2O. Các hệ số cân bằng a, b, c, d, e là các số nguyên tối giản. Tổng (a + b) là

A.8

B.4

C.11

D.7

Nguyên tử F (Z=9), cấu hình electron anion florua là

A.1s2 2s2 2p6

B.1s2 2s2 2p4

C.1s2 2s2 2p5 3s1

D.1s2 2s2 2p5

Cho phương trình phản ứng: aMg + bH2SO4 → cMg SO4 + dS + eH2O. Các hệ số cân bằng a, b, c, d, e là các số nguyên tối giản. Tổng (a + b) là

A.9

B.7

C.11

D.4

Fill in the blanks with all of the possible relative pronoun(s)

 (who/which/that) (whom? that?)

1.      Those records, _______ he owns, are mostly classical.

2.      The rumour _______ we heard about it yesterday is not true.

3.      The boy and the dog _______ were lost in the forest hunt have been found.

4.      We saw many soldiers and tanks _______ were moving to the front.

5.      Do you know the boy _______ sang the song “Happy New Year” last night?

6.      Have you heard about the earthquake _______ occurred in California?

7.      His girlfriend, _______ he trusted absolutely, turned out to be an enemy spy.

8.      Is this the style of hair _______ your wife wanted to have?

Fill in the blanks with all of the possible relative pronoun(s)

 (who/which/that) (whom? that?)

1.      The man _______ you met at the party last night is a famous doctor.

2.      That man, _______ you lent money last week, has gone.

3.      The girl _______ chatted with him yesterday arrived here at 6:30.

4.      The policeman _______ caught the criminal received a reward.

5.      I’m reading a book _______ I bought in Sydney in 1996.

Fill in the blanks with all of the possible relative pronoun(s)

 (who/which/that) (whom? that?)

1.      The man _______ you met at the party last night is a famous doctor.

2.      That man, _______ you lent money last week, has gone.

3.      The girl _______ chatted with him yesterday arrived here at 6:30.

4.      The policeman _______ caught the criminal received a reward.

5.      I’m reading a book _______ I bought in Sydney in 1996.

Complete the sentence, using either the active or passive voice of the present perfect tenses of the verbs in the box

build         examine      steal      know

       finish       transform       live      learn

1.      The old castle ______________ and it is now a luxury hotel.

2.      We are good friends. We ______________ each other for a long time.

3.      I left my bicycle here and now it’s gone. My bicycle ______________.

4.      They ______________ their assignment.

5.      The sick child ______________ by the doctor.

6.      The bridge ______________ since last year.

7.      They ______________ in London for over ten years.

8.      She speaks English fluently. She ___________ English since she was 

Change into passive voice (chuyển thành câu bị động)

      1. Somebody has taken some of my books away.

         → ....................................................................................................................................................

      2. They have provided the victims with food and clothing.

         → ....................................................................................................................................................

      3. A sudden increase in water pressure has broken the dam.

         → ....................................................................................................................................................

      4. Luckily for me, they haven't called my name.

         → ....................................................................................................................................................

      5. They have bought the land next to my house.

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