—Please don't step on the grassland. Can't you see the sign "______ the grassland" ?—Sorry, sir! I didn't see it.
---I don’t know _______. Can you help me? ---I think you should calm down and read texts.
I wanted to buy a copy of The Youth, but there was _______ left in the bookshop. _______has just bought the last one.
We must be strict _________ our work and strict _________ ourselves.
You seem ___________. What are you____________?
These broken pieces of plates don’t fit together, they ___________ parts of different ones.