1)We can change the characteristics (properties) of steel in various ways. 2) Can students bring mobile phones to class? 3) You could develop passenger liners, jets or helicopters for our aviation. 4) He will be able to solve this problem. 5) You can (you are allowed) to use dictionaries. 6) Can I open a window? 7) Should I stay here? 8) Would you like a cup of coffee? 9) You must not come in because you are late. 10) Today it can snow. 11) Although all metals can be produced in the form of a powder, only some of them are used in industrial production. 12) Is he still sleeping? 13) Do not dare to enter the room until I say. 14) You can go home. 15) Products can be bought at the store. 16) Can I use your computer? 17) They could clean up after eating. 18) Temperatures can vary over a wide range. 19) I had to solve this problem. 20) He asked if he could lend a car. 21) Mr. Morgan, you can take part in the debate on Saturday. 22) The President is convening (due by prior arrangement) the UK next month. 23) We will be allowed to use dictionaries. 24) Can I sit next to you? 25) He must have never been abroad. 26) Jack said you can go to the party. 27) Can I open a window? 28) She could, and help me with this difficult task. 28) We were allowed to stay at home. 29) He will be able to speak English fluently if he spends several years in the UK. 30) No need to rush, we have a lot of time. 31) All students must take coursework on time. 32) Did you have to wait a long time for the bus? 33) I had to (by agreement) give an answer before two in the afternoon. 34) You cannot go fast here. 35) You did not need to include this in your report. 36) I am afraid that he will not be able to return on time. 37) Maybe she has already arrived. You should call her. 38) You can very well do this job. 39) Why were you forced to make such a decision.
ответ: 1: Модальный глагол Must имеет общее значение долженствования и употребляется для выражения необходимости совершения действия в силу определенных обстоятельств, а также для выражения приказания или совета.
2) В этом значении глагол must употребляется только в утвердительной форме и переводится на русский язык словами «должно быть», «вероятно», «по-видимому», «скорее всего». All people are wearing hats. It must be cold outside.
3) говорит о том, что что-то необходимо (или наоборот, нельзя делать) делать.
4) нельзя, не должны, не должен и т.д.
5) Этот модальный глагол имеет две формы: can - для настоящего времени, could - для Употребляется он: Для выражения возможности или совершения действия. В этом значении переводится как "мочь", "уметь".
Объяснение: