1. We from London. am
is
are
2. It black.

am not
aren't
isn't
3. These oranges blue.

am not
isn't
aren't

Are

Isn't

Aren't

1. are

2. isn't

3. aren't

Объяснение:

Надо запомнить такую простую формулу:

I  am

You/We/They  are

He/She/It  is

p.s. в третьем слово oranges(апельсины) можно поменять со словом they(они)