Complete the text with the modals and semi-modals below. Use each word only once. can - must - have to - had to - can't - couldn't - shouldn't - were able to At times all of us (1) …………………… memorise things but not everyone has a good memory. Actors may forget their lines when they are on stage. That (2) …………………… be really embarrassing! Students sometimes study hard for exams then find that they (3) …………………… remember anything they've learned. According to scientists, the best thing to do if you want to learn something well is sleep. In one study, 84 college students (4) …………………… listen to a list of words. Immediately afterwards, they were asked to say the words they had heard. They (5) …………………… do this quite easily. However, later in the day, they (6) …………………… remember them. But the next morning - after a good night's sleep - they had no problem remembering the words again. Scientists believe that our brains (7) …………………… form memories better when we are asleep than when we are awake. It seems that students (8) …………………… stay up late studying the night before an exam. They need to get a good night's sleep instand.