Đốt 7,75 gam photpho trong oxi dư rồi hấp thụ toàn bộ sản phẩm vào bình đựng 100 gam NaOH 25%. Nồng độ phần trăm các chất trong dung dịch thu được sau phản ứng là

cho hai điện tích q1=q2=5.10^-9 C đặt tại hai điểm cách nhau 10 cm trong chân không độ lớn cường độ điện trường tại điểm nằm trên đường thẳng đi qua hai điện tích và cách đều hai điện tích bằng

4cos^5*x*sinx-4sin^5*x*cosx=sin^2*4x giải phương trình giúp mình với

Vì sao khi bước ra khỏi cuộc chiến tranh thế giới thứ 2 tuy với tư thế của người chiến thắng nhưng liên xô vẫn chịu những tổn thất nặng nề

cho tứ giác ABCD có Ab= BC, AD=DC a) chứng minh BD là đường trung trực của Ac ,b) tính các góc của tứ giác ABCD biết b-d=10, a-b=21

Chuyển các câu sau về QKĐ 1- We move to a new house 2- they bring a sandwich 3- he doesn't do the homework 4- they sell cars 5- does he visit his friend ? 6- she buys a book 7- the teacher punishes the boy 8- the little girl laughs at the beggar 9- they know it 10-he does not tell lies 11- they do not wait for anybody 12- who teaches English ? 13- the masons build the house 14- they invite us to their party 15- his manners disgust me 16- she sings a lovely song 17- it is time to start 18- he wants to kill the snake 19- his conduct surprise me 20- i want you to come with me Hộ em với ạ - em cần gấp - thưởng kịch số điểm ạ

Hai đường thẳng xx' và yy' cắt nhau tại o và gọi m là tia phân giác của góc xoy, on là tia phân giác của góc x'oy'.Chứng minh om và on là hai tia đối nhau

Viết số mũ trên máy tính như thế nào ạ?

giúp em mấy câu hỏi này vs ạ . 1. The preparation .................... by the time the guest....... A. had been finished - arrived b. have finished - arrived C. had finished - were arriving D. have been finished - were arrived 2. The boy......... by the teacher yesterday . A punish B.punished C. punishing D. was punishing 3. '' Ms Jones, please type those letters before noon'' - " They 've already ........., sir, They're on your desk" A. typed B. been being typed C. being typed D. been typed 4. Sarah is wearing a blouse. It ....... of cotton A. be made B. are made C. is made D. made 5. They had a boy..... that yesterday . A. to do B. done C. did D. do 6. We got our mail ........ yesterday. A. been delivered b. delivered C. delivering D. to deliver 7. James ...... news as soon as possible A. should tell B. should be told C. should told D. should be telled 8. My wedding ring ......... yellow and white gold. A. is made B. is making C. made D. make 9. Mr. Wilson is.... as Willie to his friend . A. known B. knew C. is known D. know 10. Refrences........ in the examination room. A. not are used B. is not used C. didn't used D. are not used 11. there's somebody behind us. i think we are .................. A. being followed B. are followed C. follow D. following 12. Have you ..... by a dog? A. bite B. bit C. ever been bitten D. ever been bit 13. It ......... that the strike will end soon. A. is expected B. expected C. are expected D. was expected 14. it is ........ that many people are homeless after the floods. A. was reported B. reports C. reported D. reporting 15. beethoven's Fifth sympony.... next weekend. A. is going to be performed B. has been performed C. will be performing D. will have perform 16. english has become a second language in countries like India, nigeria or Singapore where ....... for administration, boardcasting and education A. is used B. it is used C. used D. being used 17. ............ yet ? A. Have the letters been typed B. Have been the letters typed C. Have the letters typed D. Had the letters typed 18. The telephones .......... by Alexander Graham Bell. A. is invented B. is inventing C. invented D. was invented 19. Lot of houses .... by the earthquake . A. are destroying B. destroyed C. were destroyed D. is destroyed 20. Gold..... in california in the 19th century . A. was discovered B. has been discovered C. was discover D. they discover

Mb thuyết minh về cây hoa sen hay nhất