Combine each pair of sentences to make one sentence, using the words given in brackets.
1, Lang Lieu couldn't buy any special food. He was very poor.  (because)

2,During Tet, Vietnamese people buy all kinds of sweets. They make Chung cakes as well.     (so)

3,The Hung King Temple Festival was a local festival. It has become a public holiday in Viet Nam since 2007.     (however)

4,At the Mid-Antumn Festival, kids can sing, dance, and enjoy moon-cake. Every child like it very much.    (therefore)

5,We don't celebrate the festival. It costs to much money.    (if)

6,Most people book tickets long in advance. They cannot return home for Tet.   (otherwise)