Which two of these statements are true about mammals? the females have mammary glands. the females give birth to live young. they breathe using gills. their endoskeleton is made up of chitin.

The answer to this is The Females give birth to live young and their endoskeleton is made up of chitin. 

The statement they breathe using gills isn't the right answer because that is part of fishes not a mammal and fishes lay eggs not live young. 

The statement the females have mammary glands isn't right because only male mammals have that.

So your true statement is The females give birth to live young and their endoskeleton is made up of chitin.

Hope this helped :)
Have a great day 

That is true it is called an aftershock