Select the instances in which you should include a comma. o to set off an introductory phrase
O to start a list
o to show possession
o to separate day from year in dates
o to set off text inside quotes
O to separate a city and a state
O to separate the words in a series

Skill check questions rearrange the paragraphs below into the correct sequence. that's because engineers on the ultraclean project have invented a self-cleaning, antibacterial metal surface that repels water with an intricate layer of laser-engraved valleys. when it rains, the lotus does not become damp; the water simply trickles off in fat droplets, taking any bugs and dirt with it. the drudgery may not be around much longer, however, if a team of italian scientists has anything to do with it “it's simply an amazing plant,” concluded professor luca romoli, leader of the project, “and we've succeeded in mimicking it. magnifico! ” few tasks in life hold less joy than scrubbing the ghost of somebody else’s porridge from a saucepan. the starting point for the research was the leaves of the lotus flower.

(1) fire extended humans’ geographical boundaries by allowing them to travel into regions that were previously too cold to explore. (2) it also kept predators away, allowing early humans to sleep securely. (3) fire, in fact, has been a significant factor in human development and progress in many ways. (4) other obvious benefits of fire are its uses in cooking and in hunting. (5) probably even more important, however, is that learning to control fire allowed people to change the very rhythm of their lives. (6) before fire, the human daily cycle coincided with the rising and setting of the sun. (7) with fire, though, humans gained time to think and talk about the day’s events and to prepare strategies for coping with tomorrow. the sentence that expresses the main idea is: (type the number of the sentence. then click “go.”)

Which word best describes the author's tone in this excerpt from "that spot" by jack london? i don’t think much of stephen mackaye any more, though i used to swear by him. i know that in those days i loved him more than my own brother. if ever i meet stephen mackaye again, i shall not be responsible for my actions. it passes beyond me that a man with whom i shared food and blanket, and with whom i mushed over the chilcoot trail, should turn out the way he did. i always sized steve up as a square man, a kindly comrade, without an iota of anything vindictive or malicious in his nature. i shall never trust my judgment in men again. why, i nursed that man through typhoid fever; we starved together on the headwaters of the stewart; and he saved my life on the little salmon. and now, after the years we were together, all i can say of stephen mackaye is that he is the meanest man i ever knew. a. excited b. ironic c. indignant d. playful