Bonjour j’espère que vous pouvez m’aider s’il vous plaît À faire les deux exercices suivants s’il vous plaît aidez-moi

Bonjour
-ask for permission : Can
- express impossibility : Can't
- give a piece of advice : Should
- talk about the future : Could
- talk about the rules and obligations : Must
Traduire :
a- Could you explain this sentence to me ? What does it mean ?
b- You should speak louder, we can't hear you !
c- Can I open the window please ? It's too hot.
d- Can you turn on the light ? I don't see anything on the board.