Article summary practice #2 In the article, “Shocking Truth About Piranhas Revealed”, the writer Richard Connif stated the objection in responding to mass media exaggerating the fact about piranhas incidents in Argentina. In order to find the truth, the writer experimented the piranhas by exposing himself in a few different places where piranhas were. His experiences were stated in his book “Swimming with Piranhas at Feeding Time”, where he concluded that piranhas do become ferocious a few times but only when their food source concentration is high. The writer also added the opinions of others to support his argument. Jan H.Mol, the Surinamese fish biologist, also agreed to the writer that piranha threat is overly exaggerated. Based on his experience, the injury he get from piranhas was none during his research over the past 20 years. According to the Brazilian researcher Ivan Sazima, unlike widely known, piranhas feed by taking small bites of surfaces from other fish. He also urged that attack of piranhas should not be the cause of human death. It was more likely that piranhas scavenged on the dead body. For most cases of living victims, their wounds were only minor, and a factor was accompanied with each case to attract the piranhas. Mol suggested the piranhas may have attacked human by mistake because of the piranhas’ source of food was accompanied with the victims, while other specialists argued the incidents were due to defensive biting. Mol also stated that swimmers encountering the piranha male territory during the mating season could be another reason for the injury. In the end, the writer summed up the piranhas potentially be dangerous, but most cases not as extreme as the media had reported.

Article summary #1 - Health Canada banning trans fat This article discusses about Health Canada’s announcement of banning trans fat which will take effect next year. Basically, trans fat contains hydrogenated oils, or artificially generated oil which raises the “bad cholesterol” and lower the “good cholesterol” in our body. If trans fats are constantly consumed, they will accumulate in our blood vessel and prevent smooth blood circulation. This in the end may lead to heart attack, stroke, etc. Trans fats are used in variety of food products, including production of pastries, baked goods and some packaged goods to extend shelf life. The exact date of the ban taking effect will be September 15, next year which gives the food industry time to find the trans fat alternatives. Canadian researchers estimate a ban could prevent 12,000 heart attacks in Canada over 20 years.

Is this sentence correct? I was amazed by how fluent your Korean is especially considering the fact you've been self taught. Thank you in advance!

"I might have been misunderstood for..." Is "I might have been misunderstood for a different person" correct?

Exchange with / exchange for I'm a little confused with the usage of "exchange with" and "exchange for". Do they have the same meaning? If not then how do you use each of them in what occasion? Also is "You should exchange your (recently bought wrong sized) shoes with different size shoes" correct?

Does "his foot got caught between two rocks" make sense? If not, what is the correct / more natural expression of this sentence?

Does "it" in this sentence necessary? If there should be a global nuclear war, life on earth as we know it would end forever. In this sentence, I don't quite understand why there is "it" between "know" and "end" in the last phrase. Could someone please explain why? Also, is omitting "it" between "know" and "would" okay? Does the sentence make sense without "it"?