Answer:
a glass of muddy water
Explanation:
Pure substances contain only one element or compound.
Calcium is one element so it is a pure substance. Ice and water have the same molecular structure, so it is a pure substance. Aluminum oxide is a chemically pure compound.
The only example that is not a pure substance is muddy water due to the multiple components of mud mixing with the components of water.
Hope that helps.
Answer:
Narrow-spectrum antibiotics target a few types of bacteria. Broad-spectrum antibiotics target many types of bacteria. Both types work well to treat infections. But using broad-spectrum antibiotics when they're not needed can create antibiotic-resistant bacteria that are hard to treat.
Answer: Directional selection
Explanation:
In the population genetics, directional selection is the mode of selection during which the extreme phenotype are favored more than the other phenotype.
This causes the allele frequency to shift towards the time in the direction of that particular phenotype.
Here, in the question the acid tolerant plant species is favored over the other phenotype.
Hence, the correct answer is option D
Skeletal system.
Without a proper skeleton, we would not have enough rigidity to properly move. We'd be an awkward pile of skin, muscle & bodily fluids.
Hope that helps!
