科学美国人听写

i hope you have all finished reading the sin,,,, charpt on insurence, so that you are perpared for our discussion today . before we start, i'd like to mention a few things your textbook doesn't go into.it is interesting to note that insurence has excisted in some form for a very long time. the earlier insurence policies we all called botoom contract. They provided shipping protection for mechanism for back 1300 b.C. In general, the contracts were no more than vebal agreements, they gr...baozheng the loans to merchans with understansing that for particular shipment of goods lost in the sea, the loan didn't have to be repayed. Interests on the loans vary according to how risky it was to transport the goods. During peroids of havery paricy on the sea for example, the amount of interests stand for the cost of paricy went up considerably. So, you can see how inserunce helped encourage international trade, even the most caustion merchans became willing to risk ship their goods over long distances not mention in harzder weather conditions. When they had this kind of protection aviable. Generally speaking, the basic form of insurence policy has been pretty much the same since the middle ages.There are four points there are sailing then and remain pzuigaode in all policies today. These are ouutlined in charpt six,and we will serve the bases for the rest of discussion. Can anyone tell me what one of those points might be?


SSS60 植物长刺
Plants thrive all over the planet, despite the facts that many animals love to sanck on them. Varies on htper account for all those plants. One is that predators kill enough plenty animals to give vegetation chance, another is that plants develop physical and chemical means to defend themselves. Now researchers have teeees out some of these facts in the east of Afaric SSKKA. Epola and African anterlop is ,,,,, in trees and ,,, itself eaten by wild dogs and hypers. Epola often ,,,,,,, akashia. Some oksheia has thorns and some don't. The reseachers found that epola perhaps not surprisingly prefer athorant akashia. Also the animals avoide the wood areas where predstors are more likely to hide. And as a result, the thron velunverble and wood areas are plenty for predators. But akashia are more numourious when they need to defend themselves. The study is in the journal science. The researchers say that their finding show both plants defends and ,,,,,, predators help plants thrive. They also say when humans' influence inpart elimilating by large predators we disrupt longstanding complex system.


hcgz11yjh

930523

182********

220512 n0265