cho P=x^2-2xy+y^2+1,dùng kĩ thuật"nhóm thành bình phương" để chọn nhận xét đúng nhất

tại sao hiện tượng song song ngược chiều của hệ thống mao mạch lại tăng hiệu quả hô hấp ở chim và cá vậy ạ

giải dùm mình với mình cần gấp vote 5 sao cho câu trả lời sớm nhất cảm ơn nhìu

trình bày cách làm câu c vs câu d nhanh nha cảm ơn

An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. At the Earth's surface, earthquakes are recognized (25) _______ vibration, shaking and sometimes displacement of the ground. The vibrations may vary in (26) _______. They are caused mostly by slippage within geological faults, but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. The underground point of (27) _____ of the earthquake is called the focus. The point directly above the focus on the surface is called the epicenter. Earthquakes by themselves rarely kill people or wildlife. It is usually the secondary events (28) _______ they trigger, such as building collapse, fires, tsunamis (seismic sea waves) and volcanoes, that are actually the human disaster. Many of these could possibly be avoided by better construction, safety systems, early warning and (29) _______ planning. 25. A. in B. with C. as D. from 26. A. Magnitude B. value C. amount D. quantity 27. A. source B. origin C. center D.epicenter 28. A. who B. what C. that D. those 29. A.evacuator B.evacuate C.evacuating D.evacuation CHỌN ĐÁP ÁN ĐÚNG VÀ GIẢI THÍCH , PLEASE ( MK CẦN GIẢI THÍCH CHI TIẾT CHÚT NHÉ )

Giải PT : cot(x/3 + 20độ ) = -căn 3/3 . Chi tiết càng tốt ạ thanks

Mong đc giúp đỡ bài tập này mk cần gấp ạ

A = $2^{ 2^{10n + 1} }$ + 19 . Chứng minh rằng A là hợp số

giải phương trình: sin(pi/6+2x) =-1

I. Give the correct form of verbs: Look up get over turn down look after 1. Who will ………………. your house while you are away? 2. She ………………….this word in this dictionary for 10 minutes. 3. They didn’t know how …………………..this terrible natural disaster. 4. He invited her to his party but she ……………….. II. There is one mistake in each sentence. Underline and correct it. 1. Mai wishes she can make a informed decision ……………………… 2. I find this traditional craft village is interesting ………………….. 3. She wondered if to go to Da Lat in the winter. …………………… 4. Children didn’t used to wear uniform to school. ……………………….