The main task Is to make the laws.
Answer: a. Discharged, untreated, into surface waters.
Explanation:
Most of the waste water and sewage water is left untreated into the surrounding soil or water which is the main cause of pollution. Due to lack of drainage system or septic chemical treatment the sewage water drain from major cities is discharged into the surface water untreated. This water can deteriorate the quality of portable water and can affect the population of many aquatic species reducing the aquatic biodiversity. The sewage discharge consists of nitrogen and phosphorus like minerals which can result in algal bloom causing eutrophication.
Answer:
This is an example of double-blind design.
Explanation:
Double-blind design refers to a type of experimental design. It is common for participants to be divided into two groups, the experimental group and the control group. The experimental group is the one that will take the new drug, while the control group takes the placebo. Normally, the experimenter would know to which group each participant belongs, although participants themselves wouldn't know. When neither the experimenter nor the participants know to which group they belong, we have a double-blind design.