Answer:B. 7 percent, one-third
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Answer:
The diameter of a circle is the distance from a point on one side of the circle to a point on the other side going through the center. It also is expressed as twice the radius, which is a line measured from the center to any point on the circle.
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Answer:
a) calculating the concentration at which 50% of the test organisms of a particular species die 
Explanation:
Bioassays -
<u>Bioassays is an analytical method to assess the effect of marine pollutant on the organism by estimating the concentration at which 50% of the test organisms die after exposing the test organisms for a specified time.</u>
It can be done  by quantitative or by qualitative experiment , or direct or indirect .
It is used to detect the biological hazards or give the quality assessment of the mixture .
It is also used for the monitoring the quality of water .