em gạch chân mấy cái câu đó mới làm đc

Gọi n_CuO = x ; n_Fe2O3= y trong 20g hh

 80x + 160y = 20 (I)

CuO + 2HCl  CuCl₂ + H₂O

x ------> 2x (mol)

Fe₂O₃ + 6HCl  2FeCl₃ + 3H₂O

y -------> 6y (mol)

 2x + 6y= 3,5 . 0,2 = 0,7 (II)

Từ (I)và(II)  

%^mCuO =  . 100% = 20%

%^mFe₂O₃ = 80%

Giúp mình bài này với các bạn

I. Choose the word, which is pronounced differently from the others.

1. A. wanted   B. flooded         C. destroyed     D. Erupted

2. A. stops     B. wants         C. plays        D. Looks

3. A. goes     B. watches       C. fixes          D. Brushes

4. A. destroyed       B. killed      C. moved          D. Looked

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6 A. pollution B. question        C. action           D. Education

7. A. erupted    B. happened      C. destroyed     D. Buried

8. A. communit  B. computer      C. museum       D. Customs

9. A. whole  B. when            C. where          D. What

10. A. nation   B. question        C. action           D. Pollution

11.A. collapsed   B. erupted         C. scattered      D. Moved

12. A. mind   B. bike          C. tradition        D. Scientific

13. A. my         B. berry            C. hobby       D. Factory

14.A. healthy     B. team         C. tea         D. Beach

15.A. destroyed        B. raged       C. wanted         D. Killed

16. A. this      B. thankful    C. there          D. Though

17. A. physical       B. visual        C. music       D. Because

18. A. invent        B. debris           C. helpless        D. News

19.  A. provide    B. product      C. profess         D. Produce

20.  A. lit      B. sight             C. fine              D. Mine

21.A. glad       B. blame           C. clap              D. Flag

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24.A. fear    B. hear               C. clear              D. bear

25. A. invent     B. debris           C. legend          D. News

26. A. played       B. frightened     C. excited         D. Bored

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28. A. washed       B. attended   C. decided     D. Disappointed

29. A. seafood     B. good         C. flood        D. Roommate

30. whom     B. when        C. what              D. Why

Living in a city has a (1)______lot____ of drabacks.Firstly, there is the problem of traffic(2)______jams____ and traffic accidents(3)______in____ population and the increasingnumber of vehicles have(4)____caused_______ many accidents to happen everyday. Secondly, airpollution(5)___negatively______ afects people's health, and is also has a bad(6)__influence___on theenvironment. More àn more city dwellers suffer from coughing or breathing problems.Thirdly,the city is noisy, eve at night.(7)__Noise__ pollution comes from the traffic and from construction.Building are alwways being knocked down and rebuilt.These factors contribute to making city life(8)____more__ dificult for its residents