Укажите пару формул веществ, в молекулах которых есть только σ-связи:<img src="/close/store/examRes/%7B6591504D-D5D6-4E50-9945-1AFD3029A39C%7D/%D0%BE%D1%82%D0%B2%D0%B5%D1%82%202%20%D0%BA%20%D0%B2%D0%BE%D0%BF%D1%80%2016.bmp" /><img src="/close/store/examRes/%7B6591504D-D5D6-4E50-9945-1AFD3029A39C%7D/%D0%BE%D1%82%D0%B2%D0%B5%D1%82%201%20%D0%BA%20%D0%B2%D0%BE%D0%BF%D1%80%2016.bmp" /><img src="/close/store/examRes/%7B6591504D-D5D6-4E50-9945-1AFD3029A39C%7D/%D0%BE%D1%82%D0%B2%D0%B5%D1%82%204%20%D0%BA%20%D0%B2%D0%BE%D0%BF%D1%80%2016.bmp" /><img src="/close/store/examRes/%7B6591504D-D5D6-4E50-9945-1AFD3029A39C%7D/%D0%BE%D1%82%D0%B2%D0%B5%D1%82%203%D0%BA%20%D0%B2%D0%BE%D0%BF%D1%80%2016.bmp" /> <img src="/img/23/7146a3ec307c8ea66726d9657c.bmp" />, <img src="/img/48/088f14cd5be2388d4027309b60.bmp" />, <img src="/img/9a/534b34050717e1630fcfca2592.bmp" />, <img src="/img/5f/fcf678604f8547bb71eb00fe2b.bmp" />