When the speaker is lowered into water, does the frequency of the sound increase, decrease, or remain the same

a lot of it means it can be "burned" for energy and sold at one price. if it is scarce, the price will go up

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.