мышь и землеройка принадлежат к разным отрядам класса млекопитающих-грызунам и насекомоядным,но очень похожи по величине и форме тела. Как объяснить это сходство?

помогите написать Лист до Петрарки

Ацетилен можно получить реакцией взаимодействия карбида кальция с водой СаС2+2Н2О=С2Н2+Са(ОН)2 Из 1 кг технического карбида кальция реакция с водой получили 300 л ацетилена.Вычеслите массовую долю примеси (в %) в этом образце карбида кальция

1 His failure ...... the exam meant he couldn't apply for the job in London. 2 She looks familiar ....................... me. Maybe she's an actress. 3 As he was familiar ....................... Japanese culture, he wrote an article on it. 4 I'm so fond ....................... skiing that I go for a week every winter. 5 London is famous ....................... its black taxis and red buses. 6 He was very fortunate ....................... finding a publisher for his book. 7 Tony was furious ....................... Jane for spending their savings on clothes. 8 Kevin's not very good ....................... football. He'd rather play squash. 9 My grandfather was always good ....................... my grandmother. 10 Paul is a genius .................... mathematics. 11 I haven't heard ....................... Sarah yet. I hope she will write soon. 12 Everybody has heard ....................... tea. You can buy it everywhere. 13 The police say that there is no hope ................... finding the stolen painting. 14 We’re having a picnic on Sunday so we're all hoping ..................... fine weather. 1 at, to, in 2 with, to, for 3 with, to, for 4 at, of, for 5 of, from, for 6 about, in, at 7 to, with, by 8 in, to, at 9 to, at, of 10 at, with, on 11 of, from, by 12 from, for, of 13 in, of, for 14 for, to, at