cho hình chóp s.abc có đáy abc là tam giác vuông cân tạic, sa vuông với đáy, tâm của mặt vầu ngoại tiếp s.abc là điểm nào dưới đây a, trung điểm SA b, trung điểm SB c, trung điểm SC d, trung điểm AB

Mọi người lm ơn giúp em vs ạ ! 5h45 em phải nộp rồi ạ ! Em cảm ơn

1. There are several means of mass communication. The newspaper is one. Television is A. another B. other C. the another D. the other 2. They asked me a lot of questions, I couldn't answer. A. much of which B. both of them C. neither of which D. most of which 3. Actors and pop stars are known for their extravagant spending habits and end up broke. A. them all B. many of whom C. many of them D. many of which 4. He had spent time writing an essay on his childhood. A. a few B. a large number of C. a great deal of D. many 5. The writer has finished his new novel. A.most of B. most C. all most D. almost

63.We believed that Alice would pass the driving test. It was believed that Alice would pass the driving test Alice 64.The director notifies that all the workers will have to work extra hard this month. It___________________________________________________________ All the workers____________________________________________________ 65.They have decided that the company will go to the beach together at the weekend. It___________________________________________________________ The company____________________________________________________ 66.People think that Maradona is the best football player in the 20th century. It___________________________________________________________ Maradona____________________________________________________

1. I don't have enough money to buy that electric bike - I wish ............................................................................. Các bạn ơi giúp mình với mình sẽ vote 5 sao cho.

1. Only three of students in my class are girls, are all boys. A. the other B. others C. other student D. the others 2. Researchers have discovered 2,000 types of new plants but also say are at risk. A. many B. much C. the other D. variety 3. There is too bad news on TV tonight. A. many B. much C. a few D. a little 4. He bought three shirts; one for him and for his children. A. others B. the other C. another D. the others 5. study hard before an examination. A.Most the students B. Most of the students C. Most of students D. Almost students

Nhanh đi các bạn ơi, mik sắp phải nộp rồi ạ

giúp mình với ạ mình cần gấp ạ:Tính giá trị biểu thức a)A=x^2y+y^2x biết x-y=1 và x^2+y^2=5/2 b)B=x^6y+y^6x với x^2+y^2=5 và x+y=2

giúp em với ạ em cần gấp huhu @@

Thông thường tai ta nghe được âm thanh có tần số bao nhiêu Hạ âm là gì? Siêu âm là gì? Tần số là gì? (ĐƠn vị)