1.my parents (to trevel) to different countries when they (to be)young

1)the best;

2)better;

3)more;

4)the worst;

5)many.

may i come in?

you may take my pen

i can`t  catch up with her

i can play the piano

i must do it well

you must not go there

you should work more seriously

you should not read about it