7,8,9,10,12 incorrect
11 correct
13 London is a very big city.
14 Sometimes I go to the beach in summer.
15 There are 12 people in our class.
16 How do you spell city?
17 My brother goes running in the evening.
18 They have just arrived in London.
19 Whose book is this?
20 Where did we (you) find it?