This is a bit subjective because this particular work is difficult to classify, but in general many would agree that it is a thematic work of documentation.
Answer:
1) semicolon
2) comma
3) semicolon
Explanation:
semicolons are used to separate two independent clauses. Independent clauses are phrases that make sense on their own. The comma is needed in #2 because the phrases don't make sense on their own. In that case, a semicolon wouldn't work there.
The same thing that happened in the 19th century, "The Great Stink". The name is real and it describes an event from the past which would repeat if they started throwing waste again. The river would become so polluted that disease and contagion would begin to spread. In the 19th century, it was cholera. Now, nobody knows.
Answer: His arms muscles work in pairs so that one contracts while the other relaxes as he climbs up.
Explanation: when we exercise one muscle, there is usually another muscle that isn't the target of the exercise but it helps us maintain the form by doing the opposite movement. For example, when we do a bicep curl, the muscle that we are working is the biceps, and it contracts, but at the same time, the triceps relaxes, this is called antagonist muscles. The same thing happens when a rock climber climbs up the rock wall, the biceps contract as he pulls up and the triceps relax at the same time.
