10x + 2x - 4 = 5x + 4x + 2 hoi x=

II/ Choose the best answer:

31/ They knew each other when they --------------------- in France.

A. study                   B. are studying                   C. have studied                      D. were studying

32/ There ------------- a lot of grass in the field last Summer.

A. are                        B. is                             C. was                               D. were

33/ I knew that she --------------- waiting for somebody.

A. would                      B. is                     C. seemed                 D. was

34/ Mr. Minh didn’t --------------------- in California.

A. lived                       B. use to live                 C. use to living            D. used to live

35/ Whose father --------------?  - I phoned Kim’s father.

A. did you phone       B. was phoning you        C. you phoned           D. phoned you.

36/ What ‘s the matter? You -------------- very happy.

A. look                      B. don’t look              C. are looking                 D. aren’t looking

37/ Don’t try to ring the bell. It ----------------

A. is working               B. works                      C. isn’t worked             D. doesn’t work

38/ He can’t go out because he ---------------------- his work.

A. don’t finish           B. didn’t finish             C. hasn’t finished           D. had finished

39/ How many cups of coffee have you -------------- this morning?

A. drank                     B. been drinking               C. been drunk            D. drunk

40/ I ---------------- to visit you, but I didn’t have enough time.

A. am going              B. was going                      C. would                    D. could  

I/ Put the verbs in brackets into the correct Tenses:  

1/ She ( buy ) some food yesterday. 

2/ I ( not be ) here last week. 

3/ Mrs Wilson had an accident While she ( drive) car to work this morning. 

4/ We’ll go out when it (stop) raining. 

5/ My uncle (live) in the USA since last year. 

6/ I saw her when I ( walk down) the street. 

7/ Hurry up ! the train ( come ).  

8/ Why didn’t you listen while I ( speak ) to you?  

9/ Where ………. you ( spend ) your Summer holiday last year?  

10/ Let’s go out. It ( not rain ) now. 

11/ It ( not rain ) in the dry season. 

12/ Up to now, I ( do ) every exercise in this book. 

13/ I have been here since I ( be) ten years old. 

14/ My sister always ( wash) her hands before meals. 

15/ Please don’t say anything while I ( learn) my lesson. 

16/ We were good friends. We (know) each other for a long time. 

17/ We arrived home and found that  a burglar ( break ) in. 

18/ We aren’t hungry. We ( have ) Lunch. 

19/ I had finished my work before ( go ) to bed. 

20/ While John was reading a book, Mary ( watch ) TV. 

21/ He ( return ) to his hometown recently. 

22/ She ( just come ) back from Japan. 

23/ Vietnam, Thailand, and Malaysia ( be ) tropical countries. 

24/ ……………. Your sister ( like ) lemon juice? 

25/ We ( learn ) English at the moment. 

Hai điện tích điểm bằng nhau được đặt trong nước (  = 81) cách nhau 3 (cm). Lực đẩy

giữa chúng bằng 4.10-5 (N). Tìm độ lớn hai điện tích đó

1.Cho 13g kẽm tác dụng với 100ml dung dịch HCl 3M

a. Chất nào còn dư trong phản ứng trên?

b. Khối lượng muối ZnCl₂ được tạo thành trong phản ứng này là?               

2.Trộn dung dịch có chứa 22,2g CaCl₂ với dung dịch có chứa 1,7g AgNO₃.

a. Chất nào còn dư trong phản ứng trên?

b. Tính khối lượng kết tủa thu được

Nồng độ 100ml dd NaOH cần dùng để phản ứng vừa đủ với 200ml dd HCl 0,05M là bao nhiêu?