Đốt cháy hoàn toàn 1 hiđrocacbon X, sau phản ứng thu đc 6,72 lít khí co2 ở đktc và 7,2 gam H2O A.Tìm CTPT của X B.viết các đồng phân cấu tạo của X .Gọi tên

Cho tam giác ABC cân tại a,Biết góc a bằng 30 °,Cạnh DC =2cm ,Trên AC lấy D sao cho góc CBD =60 độ .Tính AD

giúp mình hai câu này với mình cám ơn

mọi người cho mình hỏi bài này ạ 1 Rewrite the sentences so yhat it has smilar meaning as the sentense printed before using the words given 1 they will install solar panels on the roof of our house next week solar panels... 2 they will build a new school for poor children next mouth a new school ... 3 will the plumber check cracks on the water pipes in two days ? cracks ... 4 they sell these chemicals everywhere in my hometown these chemicaals ... 5 they won't show the film on types of picture energy sources next friday the film... 6 some people will interview the new president on tv the new president... 7 they will destroy the old thermal power plane at the end of this year the old thermal ... 8 they will widen the road to our village next year the road ... 9 we will be using biogas for cooking and heating at this time next mounth biogas ... 10 they got the first prize at the competition the first ...

dịch : I'm tired of everything around

viết các phân số sau theo thứ tự từ lớn đến bé:5/2,2/7,4/5,10/3,2/3,15/89

Cách nhanh nhất có thể để tính: $\frac{1}{\frac{1}{45} + \frac{1}{36}+\frac{1}{24}}= 10,9$

Anh ấy thường đi đâu vào các kì nghỉ hè? DỊCH SANG TA

Birds that feed in flocks commonly retire together into roots. The reasons for roosting commune are not always obvious, but there are some likely benefit In winter especially, it is important for birds to keep warmth at night and conserve precious food reserves. One way to do this is to find sheltered roost. Solitary roosters shelter in dense vegetation and enter a cavity- horned larks dig holes in the ground and ptarmigan burrow into snow banks- but the effect of shelter is magnified by several birds huddling together in the roost, as wrens, swifts, brown creepers, bluebirds, and anis can. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together was found to reduce their heat losses with a quarter and three together saved a third of their heat. Mọi người tìm cho mình 10 lỗi sai trong bài này và giải thích lí do vì sao sửa như thế nhé hứa 5*+ctlhn

nhiệt phân KClO3 thu được 33,6lO2 . Tính khối lượng KCLO3 biết hiệu suát là 90%