What makes us think that mars must once have had an atmosphere that was warmer and had higher surface pressure?

d is the answer i came up with

the best answer for these questions would be:

1.            c. is smaller

2.            d) concrete operational

3.            b) interaction with the environment – the children interact with their environment can them learn more.

4.            a) parents who reason openly with children can limit a child’s cognitive ability.