Answer:
C. Magnetic poles become nearer
Explanation:
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.
<span>A. Carbon dioxide levels have increased
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Alternation of generations is the fluctuation of the diploid and haploid stages in plants. The diploid stage occurs through mitosis while the haploid stage works through meisos and asexual reproduction. In vascular plants, the diploid stage produces seeds. In non-vascular plants, the haploid stage produces the spores.