Which of the following is/are always true?

Which of the following is/are always true?

A: if A∪B=B, then A⊂B

B: B⊂A∪B

C: If B⊂A, then A∪B=A

D: If Ac⊂B and B⊂C, then Cc⊂A

E: If A∪B=C and A∩C={}, then A={}

F: A∩B⊂A

G: A∪B⊂A

H: If A∩B={} and B∩C={}, then A∩C={}

I: If B⊂A, then A∪B=B

J: B⊂A∩B