1. can, can
2. can not
3. Can
4. must
5. must not
VI. The reasons are that computers are far more efficient than human beings, they have mush better memories and can store huge ammounts of information and they can do calculations in a fraction of the time taken by a human matematician.
б) 1. ...the first calculating machine.
2. Czech
3. ...1923
Well, there is a big one and a small one.
2. I had never heard this song before.
3.He had never played tennis .
4. We had never been to Mexico.
I am watching TV now.
At the moment my mother is cooking.
Kids grow up fast these days.
We'll go to the concert tonight.