It can be dangerous to carelessly teach grammar to students. what is this?

a) improper pronoun usage
b) split infinitive
c) ending a sentence with a preposition
d) subject - verb disagreement

The vertical height of a soccer ball can be represented by the following function, where h(x) represents the height, in feet, x seconds after the soccer ball is kicked. rewrite the function in the form that reveals the times at which the soccer ball is on the ground.

Which statement best expresses a claim a. although many people believe homework is a crucial part of school, there is evidence to suggest that homework may not be as valuable as once thoughtb. the amount of homework given by some high school teachers is insane and actually has negative effects on other important aspects of a student's life c. i would have so much more time to do the extracurricular activities and hobbies i enjoy if i did not have to spend most of my evenings doing homework d. some schools have adopted homework policies that limit the amount of homework that teachers are allowed to assign their students each night

What is meant by “eternally burning black pipes”? what is this implying about the personality of the firemen?