Cho tứ diện ABCD có AB vuông góc BC,BD , tam giác BCD vuông tại C. Kẻ BE vuông góc với AC , EF vuông góc AC (F thuộc AD) . Chứng minh: a) CD vuông góc (ABC) b) BE vuông góc (ACD) c) EF vuông góc (ABC)

huhu quá đáng lắm lun á k ai giải hộ bài 6 vs bài 10

Mình cần gấp lắm nha mn bài 1 thôi ạ Giúp mình với hứa combo vote+Thanks+good Mình cảm ơn trước ^^

Choose the correct word A, B, C or D for each gap to complete the following passage: Yesterday, Carlos went (11) ______ La Tomatina. The festival is held on the last Wednesday of August every year in Bũnol, Spain. (12) ______ were thousands of people there. In the morning, many people tried (13) ______ up the pole to get the ham. At 11 a.m., they (14) ______ a jet from the water cannons and the chaos began. Bags of tomatoes from trucks were (15) ______ to the crowds, and they began throwing tomatoes at one another. They all had to wear goggles (16) ______ their eyes. After one hour, they saw another jet and stopped (17) ______. The whole town square (18) ______ red with rivers of tomato juice. Finally, they tried tomato Paella, a (19) _____ Spanish rice dish. Together with local people and tourists, they enjoyed the (20) _____ food and drinks. 11.A.at B.in C.to D. from 12.A.There B.They C.That D. This 13.A.to climb B.climb C.climbing D. climbed 14.A.see B.saw C.seen D. seeing 15.A.throw B.threw C.thrown D. to throw 16.A.protecting B.protect C.protected D. to protect 17.A.to throw B.throw C.throwing D. threw 18.A.is B.are C.was D. were 19.A.tradition B.traditional C.traditionally D. traditions 20.A.good B.well C.better D. bad

Bạn nào làm được hết mình vote cho bạn ấy 5 sao

{x+y=21 {2x+y=30 . . . . . . . {x=9 {y=12 Ai giải đc giúp với ạ

giúp mk tiếng anh vs ạ mk học ngu môn này lắm

Giúp mik đi mọi người 😘😘😘😘😘😘

12-(x-8)=-2(9+x) mong Mn chỉ giúp với ạ

giúp mk vs cần gấp!!!!! sẽ vote 5*