A negative control is a sample that you know will give you a negative result. You are testing for the presence of proteins, reducing sugars, starch, and lipids in various foods. What would be the best negative control for this experiment

Starch and water will be the best negative control

Explanation:

Negative control sample is a sample that will not give change in an experiment.

Starch and water will be the best negative control. This is because, starch is broken down by HCl to monosaccharides in the Benedict test which is the test for reducing sugar

Distilled water remain a negative control because it remain blue which means it does not reduce sugar with starch solution.

Water plus us a negative control for Buiret test (protein) and Benedict(reducing sugar) because it does not indicate the presence of protein and reducing sugar.

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.

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.