Решается как обыкновенная пропорция.
Ну т. К. А - 5, то В - 4, С -3
<span>He studies English, and we </span><span>study French. John can speak French, and his sister</span> can<span /><span><span> speak English</span>. Nina goes to school, and her brother to college. My sister reads Russian books, and I read English books. Nick has got a brother, and I have got two. He's at school now, and I am at home. He lives in Moscow, and his sister lives in London.</span>