Answer:
Five hundred out of every one thousand rats would die
Explanation:
Median lethal dose LD-50 (lethal dose 50%) is used as a measure of poisoning potential of a substance. LD-50 is the dose of substance, given all at once, which causes the death of 50% (one half) of a group of test animals. LD-50 is usually expressed as the amount of chemical administered (e.g., milligrams) per 100 grams or per kilogram of the body weight of the test animal. In this example, the test animals were rats, they were administrated a certain insecticide. Administration methods that are the most common are dermal (applied to the skin) and oral (given by mouth). If the determined LD-50 is 250 milligrams per kilogram of body mass, it means that one half (five hundred) of one thousand rats would die, because we are talking about lethal doses.
B. No is correct.
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Answer:
Answer is C. An increase of about five months.
Explanation:
Air pollution is a situation whereby the air is being contaminated by harmful substances such as carbon {iv] oxide. It is a threat to plants, animals and human health.
Improving air quality is a method to reducing the level of contamination of the air to a reasonable minimum, and in the process extending the lifespan of the resident organisms.
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Answer is the first choice - form non-metals</span>. Some acid and metal reactions don't form anything especially with weak acids. But many acids react with metals to form salt and hydrogen, which are considered non-metals.
