What is the number of main idea? i need this answer .

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.

How are the two arguments made in the passages different? a. the first passage claims that pets in class will children with health problems; the second passage says pets will make some health problems worse. b. the first passage claims that students’ nervousness will decrease around pets; the second says that students’ nervousness will increase around pets. c. the first passage claims that pets will make the teacher’s work easier by keeping students busy; the second passage says pets will make the teacher’s work harder. d. the first passage claims that pets in school will be good for kids’ mental health; the second passage says pets will be bad for kids’ mental health.

Which type of story uses animals as characters in order to illustrate a general truth about human nature?