The cost of renting a house in central Jurong is more than      in any other area of the city.

―Who is making so much noise in the garden? ―___________ the children.

 More and more people find ______ necessary to protect our earth. 

 -- Did you read a book about customs last week?-- Yes, I found ______ very useful to know the customs of foreign countries.

— _______ does Tom like math? —Because _____ fun.