Modal verbs

"This man is my History teacher. "

"He ... be a teacher. Helooks too young"

" ...I help you, madam?"

"Yes, please. I`m looking for the shoe department"

"I`ve lost my passport"

"You... to report it to the police office"

...I invite my girlfriend for dinner, mum?

"Did you water the plants?"

"NO, I....My sister did it."