L.A gramer and stuff exam

Rewrite the sentance so it is gramaticly correct.
He saw the Moon.
he saw the moon
Where is Bob? I saw him today.
wear is Bob i saw him Today
There he is.
their he is
It's raining, we'd better get home.
its raining, wed better get home
whose got the car keys?
who's got the car keys?
What does 's mean for example It's, He's, and Who's
makes the word plural
what does singular s do
shows ownership
what does s' show