Exercise:
the following paragraph is missing five commas. using the previous rules, consider where you would (and wouldn’t) add commas to individual sentences.

many people would not view the industrial revolution as a time of poverty. while the revolution was good for the economy of the united states it was not a solution for poverty or the poor. it changed people’s lives and although they were more mobile the impoverished moved from one poorhouse to another to find work. life became easier for many citizens of course but factory life was often grueling and dangerous. the effects are still lingering today and movement between social classes is difficult for many to achieve.

1) earth's crust is made up of relatively rigid plates that ride atop earth's hot, semiliquid mantle. (2) the plates are called tectonic because they're in constant motion. (3) they can move because earth's mantle is a very hot and semiliquid fluid called magma. (4) volcanoes are a result of magma rising up or erupting through a plate, particularly where plate boundaries are moving against each other. (5) also, when plates slide against each other, causing friction along adjacent plate boundaries, earthquakes frequently occur. (6) therefore, we often find volcanoes and earthquakes along plate boundaries. (7) plates may also collide. (8) when that happens, mountain ranges are formed. (9) for example, the collision of the plate carrying the indian subcontinent created the himalayan mountains when it collided with the asian plate. which statement about this paragraph is accurate?

What is implied in this sentence from mark twain's "the £1,000,000 bank-note"? i was puzzled, and wanted to discuss the matter a little further, but they didn't; so i took my leave, feeling hurt and insulted to be made the butt of what was apparently some kind of a practical joke, and yet obliged to put up with it, not being in circumstances to resent affronts from rich and strong folk.

Which war does jonas have a memory about? in the giver.