Cho dòng điện có cường độ 2A chạy qua bình diện phân chứa dung dịch CuS0, trong 16 phút. Tính khối lượng đồng bám vào catốt. Biết đồng có đang lượng điện hóa là k= 3,316.10 g/C.

A. 0,663.10³g

B. 6,63.10 g

C. 0,764 gam

D. 0,4 gam

Tại sao phải tưới tiêu hợp lí?

III.GRAMMAR

^{_{1.      The man wanted to avoid ...................... on security cameras.}}

^{_{A. to see                         B. seeing                        C. to be seen                          D. being seen}}

^{_{2.      I saw the cat _______ through the window}}

^{_{A. jump                          B. jumping                      C. jumped                              D. to jump}}

^{_{3.      When I got to the airport, the plane ____________ taken off.}}

^{_{A. has                             B. have                           C. having                               D. had}}

^{_{4.      What ____________between 9:00 and 10:00 yesterday evening?}}

^{_{A. did you do                 B. were you doing          C. do you do                         D. had you done}}

^{_{5.      John ________ his first piece of music when he was ten years old.}}

^{_{A. was writing               B. writes                         C. written                               D. wrote}}

^{_{6.      I hope ______ in many of the school’s social activities.}}

     ^{_{A. including                        B. being including          C. to include              D. to be included}}

^{_{7.      Could you please stop _______  a newspaper on your way?}}

   ^{_{A. to buy                  B. buying                               C. buy                                    D. is buying}}

^{_{8.      Would you mind not _________ the radio until I’ve finished with this phone call?}}

^{_{A. to be turned on          B. being turned on         C. turning on                       D. to turn on}}

^{_{9.      Their crop was ______ good that they decided to give a party.
     A. very                              B. too                                 C. such                                   D. so}}

^{_{10.  We .......... lunch when we heard the news.}}

            ^{_{A. had              B. were having C. have                        D. have had}}

^{_{11.  Do you have much opportunity .......... your English ?}}

            ^{_{A. practising    B. to practise  C. practised      D. to be practise}}

^{_{12.  Your handwriting is impossible ..........}}

            ^{_{A. reading                    B. read             C. to read        D. readed}}

^{_{13.  “Did anyone see the thief ?” “No, he already .......... away by the time we .......... in ”.}}

^{_{A. ran / had come   B. runs/ have come C. has run / come D. had run / came}}

^{_{14.  Sally's low test scores kept her from _______ to the university.}}

    ^{_{a. admitting   b. to admit             c. to be admitted      d. being admitted}}

^{_{15.  I'm really ………….. to the party. All my old friends will be there.}}

^{_{A. appreciating            B. looking forward      C. thinking about   D. enjoyable}}

^{_{16.  I remember …………………. to Paris when I was a very small child.}}

^{_{A. to be taken        B. to take         C. being taken D. taking}}

^{_{17.  The examiner made us ………………… our identification in order to be admitted to the test center.}}

^{_{A. show                 B. showing       C. to show       D. showed}}

^{_{18.  The plants want………………………daily.}}

            ^{_{A. to water                   B. watering      C. to be watered  D. being water}}

^{_{19.  We are whispering to avoid                              by the other ones.}}

^{_{A. hearing           B. being hearing         C. to be heard            D. being heard}}

^{_{20.  The traffic lights ________ green and I pulled away.}}

^{_{a. turned              b. were turning             c. has turned    d. had turned}}

^{_{21.  I tried___________the bus, but I missed it.}}

^{_{a. to catch                       b. catching       c. to be caught             d. being caught}}

^{_{22.  A friend of mine phoned _______ me to a party.}}

     ^{_{a. for invite        b. inviting        c. to invite        d. for inviting}}

^{_{23.  I think your mother should let you __________ your own mind.}}

^{_{A. to make up              B. making up               C. made up                              D. make up}}

^{_{24.  The skiers would rather __________through the mountains than go by bus.}}

 ^{_{A. to travel on train                 B. travel on train       C. travel by train                         D. traveling by train}}

^{_{25.  Would you consider _____________ your share of the company?}}

^{_{A. sell                         B. selling                     C. to sell                                  D. to be sold}}

^{_{26.  Look at the state of the gate. It needs ________ as soon as possible.}}

^{_{A. to repair                  B. to repairing              C.being repaired                     D. to be repaired}}

^{_{27.  We had hardly sat down when she ________ plates of food for us.}}

^{_{A. brought                   B. has brought             C. had brought                         D. would have brought}}

^{_{28.  We hope that the students themselves will enjoy ______ part in the projects.}}

^{_{A. to take                     B. taking                     C. to be taken                          D. being taken}}