Điểm cực đại của hàm số y =  \(\dfrac{x}{\sqrt{2x^2+9}-1}\) là    

nêu phương pháp tách nhôm và đồng ra khỏi hỗn hợp biết nhiệt độ Đồng=660 độ,nhiệt độ nhôm =1084 độ

Mọi người cho em hỏi Mấy từ ever than, much more, more than, even more là từ gì và cách dùng với ạ

trên đường thẳng xy lấy điểm O.Trên cùng một nửa mặt phẳng bờ xy,vẽ hai tia Ot và Oz sao cho xOt=80 độ;yOz=50 độ

a) Tính số đo xOz và yOt?

b) Trong 3 tia Oy,Oz,Ot tianaof nằm giữa hai tia còn lại ?Vì sao?

c) Chứng tỏ Oz là tia phân giác của yOt?

Giải giúp mình với 

Cho hình trụ có thiết diện qua trục là một hình vuông cạnh 20 cm. Tính thể tích hình trụ. 

Cho hình nón có bán kính đáy R=3 cm, biết diện tích xung quanh bằng hai lần diện tích đáy của nó. Tính thể tích hình nón.

từ đặc điểm nhận dạng các đại diện của ngành lớp ĐV, nêu điểm tiến hóa từ thấp tới cao

giúp mình câu này với ? Hỗn hợp E gồm X, Y, Z đều là este no, mạch hở (trong đó X, Y đều là este đơn chức và (MX < MY < MZ). Thủy phân hoàn toàn 0,16 mol E bằng lượng vừa đủ 220 ml dung dịch KOH 1M, thu được hỗn hợp F gồm hai muối của axit cacboxylic và 10,96 gam hỗn hợp T gồm hai ancol kế tiếp nhau trong dãy đồng đẳng. Mặt khác, đốt cháy hoàn toàn 0,08 mol E cần dùng 0,595 mol O2, thu được CO2 và H2O. Phần trăm khối lượng của Z có trong E là A. 25,93%. B. 39,69%. C. 45,39%. D. 59,53%

Question 16 refers to section A on page 3.

Question 16: What is the main purpose of section A?

A. to stress the importance of environmental awareness

B. to point out the benefits of recycling

C. to invite students and parents/guardians to a meeting

D. to announce a planned recycling scheme

Questions 17-18 refer to section B on page 3.

Question 17: What do we learn about the ballet?

A. It’s only performed during the Christmas holidays.

B. There will not be many performances.

C. It will be performed at Greenhill School.

D. It’s not suitable for older children.

Question 18: Why are people asked to fill out the tear-off portion at the end of the letter? A. in order to get better seats

B. so that the school secretary won’t be disappointed

C. to inform the school about which performance time they prefer D. so the school knows how many tickets to book

Questions 19-20 refer to section C on page 3.

Question 19: What type of person would a suitable candidate be?

A. cooperative             B. introverted                C. bossy                       D. competitive

Question 20: In the third sentence of the second paragraph, what does They refer to?

A. school trips                                                    B. staff members

C. extra-curricular projects                              D. applicants

Questions 21-23 refer to section D on page 3.

Question 21: Why does the center need volunteers now?

A. It is caring for more turtles than ever before.

B. Most of its turtles are sick or injured.

C. It is experiencing an increase in visitor numbers.

D. The existing volunteers are undergoing training.

Question 22: Why does the leaflet mention sponsorship?

A. to show that some school children have little free time

B. to highlight that the center is in need of money

C. to present an alternative form of participation

D. to encourage classmates to volunteer together

Question 23: What does the section tell us about the turtles the center has?

A. The vets check their progress once a week.

B. They are placed in the sea when they have recovered.

C. Caring for them is not at all cheap.

D. Their progress can be followed on the center’s website.

Questions 24-25 refer to sections A, B, C and D.

Question 24: Which sections mention activities that could form part of Greenhill School’s extra-curricular program?

A. sections A, B and C                                      B. sections A, B and D                                     C. sections B, C and D                                             D. all sections

Question 25: What would a teacher at Greenhill school NOT be expected to do?

A. accompany children to theatrical performances

B. volunteer to help at the turtle center

C. attend activities and meetings after school hours

D. organize a tree-planting day in the school ground

Read the following sections and mark the letter A, B, C, or D on the answer sheet to indicate the correct answer to each of the questions from 16 to 25.

B

A Winter Theater Evening

Experience the wonderful world of ballet

and the music of Tchaikovsky

On December 19 and 20, the weekend before Christmas, the Vonereva Ballet Company will be dancing The Nutcracker at the Central City Theater. With its spectacular Waltz of the Snowflakes scene, The Nutcracker is always a favorite during the Chrismas period. It is said to be one of the most enioyable ballet extravaganzas for all ages, and especially children, due to its Christmas story plot, dancing toys and fabulous costumes.

Performance times will be announced next week but, in the meantime, please fill out the tear- off portion at the bottom of this letter if you are interested. Children who want to attend, but whose parents/guardians aren't able to, will be accompanied by Mrs Carlson, head of the Science Department. Due to the limited number of performances, we must book soon so as to avoid disappointment. Tickets will not exceed $10, but the bigger the group, the cheaper the tickets.

Greenhill School's Winter Theater Evening The Nutcracker

Please complete ond return to the school secretary

Name of family ___________________________

We would like _____ tickets

Signature of parent/guardian ___________________

D

The Bayside Turtle Rehab Center

Volunteers Needed

We are appealing for school children to work as volunteers at weekends. Presently, there are over 35 turtles in our care, a number which has broken all previous records, and the work involved and care they need is keeping the permanent members of staff at the center very busy.

Volunteers would be expected to do menial tasks such as cleaning, welcoming visitors, showing them round and generally

being on hand to help our trained vets when necessary. Most of our turtles are sick or have been injured, and therefore require a lot of tender loving care and attention from the vets,

If you have no time available but would like to help, you can sponsor a turtle for a small fee ($5 per month) and follow its rehabilitation and progress on a weekly basis, eventually taking part in its return to its natural environment. Perhaps you would like to do this together with a classmate.

So come along and visit us and our turtles. We'd all love to see you. We are located at Marina B2 and our phone number is 417 3831. You can also learn more about us online at baysideturtlecenter.com.

Mary Robinson – Director of Bayside Turtle Rehad Center

cm bằng pp quy nạp P(n) = 2^2 +4^2+...+(2n) ^2=(2n(2n+1)(2n+1))/3