Which objects can make shadows? (Select all that apply) 1. Refrigerator

2.clear plastic

3.backpack

4.clear glass

5.wooden door

refrigerator

backpack

wooden door

this is because clear plastic and clear glass and transparent/ translucent and therefore light passes through it not forming a shadow.

A shadow is ONLY formed if light is blocked by an object etc.

the answer to you question is   jet streams

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.