Freeze thaw weathering and onion skin weathering does not take place in the same region. explain

Ihave no idea. about. that

Humans have survived and thrived in mexico city by using technology to create greater access to land. when the spanish conquered the aztec capital, tenochtitlan, in the 16th century, they built mexico city by draining the lakes and filling in the lake water to create more arable land for agriculture. this technique of land reclamation has continued to be fundamental to human civilization in mexico city. 

Well, a and b together would be negative. b alone would also be negative.

When two tectonic plates collide and one or both push upwards they also push up the crust,a mountain will for so that will be your answer. hoped this