Подчеркните в каждом предложении модальный глагол и его эквивалент 1) at the exhibition we could see the latest track-laying machine 2) the sleepers for high-speed railways have to be made of concrete 3) some trains are to make stops at all railway stations 4) they will be able to create the necessary conditions in the laboratory
2. have to
3. are to
4. will be able