Answer: The correct sentence is: 'We have a lot of luggage.' - without the 's'.

If you got that right, well done! If not, you may need to review countable and uncountable nouns.

Answer: The correct answer is 2. 'I have lived in London for two years.' 

 'since' and 'for' are two words that often get confused. Do you know how to use them?

Answer: The correct answer is the possessive adjective 1) their.
 ‘There’ indicates location, and ‘they’re’ is a contraction of the words ‘they are’.