First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is a catalyst.
Bias is defined as any tendency which prevents unprejudiced consideration of a question. In research, bias occurs when “systematic error [is] introduced into sampling or testing by selecting or encouraging one outcome or answer over others”.
I believe the answer is D.
S PHASE
<span>Cell division involves the different phases such as G1, G2, M and S phase. Cell division is the mechanism of cells to divide into other cells. Two types of cell division is popularly called the mitosis and meiosis. There basic difference is how they function and how many chromosomes their daughter cells have. </span>
The main function of environmental policy is protecting a society's natural resources. These policies provide necessary measures to make sure all the resources remain available to everyone. The main function of environmental policy is protecting a society's natural resources.
