Can, have to, should

can you help me please?

 You  should do more sport if you want to lose weight.

 You  must do your homework first if you want me to let you go out with your friends.

 He has just broken his leg so he can't  play football.

 Drivers  mustn't drive over the speed limit.

 I can't speak Chinese: it's too difficult!

She  should take an umbrella: it's going to rain!

 We can take photos inside: it's not forbidden.

 I think we  shouldn't take this road: it's not on my map!

You look pale! You  should sit down and have a glass of water.

 We must stop when the traffic light is red.

How  can you say such a thing?

 You  should take the blue one: it suits you!      

 You shouldn't smoke so much: it's bad for health.