Tần số của hai con lắc là :

\(\dfrac{15}{t}:\dfrac{10}{t}=1,5.\)
Vậy ta thấy tần số dao động của con lắc thứ 2 lớn hơn vì nó lớn hơn 1,5 lần so với con lắc thứ nhất.

\(240g=0,24kg\)

Trọng lượng của thùng hàng :

\(200.10+0,24.10=2002,4\left(N\right)\)

Vì khi ta nhịn thở lâu sẽ làm ngưng tiếp xúc với oxygen bên ngoài,sẽ dẫn đến tử vong.

VIII. Fill in the blanks with the suitable prepositions.

1. Don’t overheat the victim___with__________ blankets or coats.

2. Put the affected part of the burn _under____________a running cold tap, if possible.

3. She fell____of_________ her bike and hit her head          ___on__________ the road.

4. What do you know____about_________ a first-aid course? Please tell me what you know.

5. The rescue team tried to take them out____of_________ the fire.

6. Will you inform your classmates ___about__________ the change ______in_______ schedule?

7. You shouldn’t take____off_________ warm clothes. It starts to be colder than before.

8. Will you come_____over________ to my place on the weekend?

Got

Have you learned 

A

Bài 2. Chia động từ trong ngoặc ở thì tương lai tiếp diễn

1. I (learn)…… will be learning…………….English at this time tomorrow.

2. My mother (go)…… will be going………………to France at this time next month.

3. They (sell)……will be selling…………..winter closes at this time next week.

4. Jim (read) …will be reading………………in the library at 3 p.m tomorrow.

5. He (not study)…won't be studying………………at that time tomorrow.

6. ………Will you be staying…………….(you/ stay) at home when I arrive tomorrow?

7. My father (watch)……will be watching ……..a soccer match on TV at 8 o’clock tomorrow evening.

8. Our teacher (teach)  will be teaching…………….Math at this time next week. 

9. Jim and Jane (go)… will be going………to the local museum at this time next week.

10. All the students (sit)…will be sitting…..the English Exam at 7.a.m. tomorrow.

11. What  will Peter be doing …(Peter/ do) at & o’clock tomorrow morning? 

12. Peter (write)…will be writing ………..a report.

13. I’m very busy tomorrow morning. I (not/play) …… won’t be playing………sport at 8 a.m.

14. ……Will the baby be sleeping………………….(the baby/ sleep)  at 9p.m. tomorrow?

15. A well – known professor (deliver)  will be delivering…….a lecture at my university at 8 a.m.

IV. PREPOSITION (05 câu)

1. Everybody attends the festivals ……………….. fun

A. with                           B. for                           C. in                              D. of

2. People celebrate it ………….. an Easter breakfast or meal.

A. with                           B. by                            C. for                             D. in

3. They decorate their house ……………… beautiful Christmas trees.

A. by                             B. on                            C. with                           D. of

4. We celebrate this festival annually …………. March 3rd.

A. up                             B. in                            C. of                              D. on

5. The card games began ……….. midnight.

A. at                              B. on                           C. in                              D. to