George dumps a bag of marbles onto the ground, scattering the marbles all over. he tells his mother that there are more marbles now. george is demonstrating that he has not yet achieved the concept of?

Conservation

Explanation:

George being demonstrating that he hasn't achieved yet the concept of conservation.

hygrometers and hair thermometers (often found as part of hygrometers/psychrometers) can be used to measure humidity. barometers are used to measure atmospheric pressure, while anemometers are used to measure wind speed. so the 2nd and 4th choices should be the correct answers.