PLEASE HELP ME WITH MY HOMEWORK!!!!!

1. A metal bar is 100cm long. It is heated for an hour. What could be the new length of the bar? a)102cm b)99cm c)98cm d)99.2cm
   
2. Why are there gaps in concrete roads?
   

a)to allow for contraction

b)cheaper

c)to allow for expansion

d)it makes it easier to repair one section of the road