make a situation where in a natural phenomenon is happening which leads to then to a disaster in a certain area including safety measure plans at the end.

The answer would be newton’s second law

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.

Ctrust me i know its c