根据第一段中“Even if you know other freshmen, you still feel anxious that you don't know any upperclassmen."可知,新生第一天来到学校时通常感到紧张。 故选D。 2. B 细节理解题。 根据第四段中“The work in senior high school is something freshmen are probably worried about. "可知,高中的 ...
Bisphenol A (BPA) is a synthetic oestrogen that is used in large quantities in the global plastics industry in the production of polycarbonate plastics and epoxy resins.
Product tracking and genealogy – groups final parts or batches with the corresponding manufacturing data, from raw materials through to component assembly. Labor management – ensures people, products and operations are in the correct place in the manufacturing process to maximize efficiency. Document ...
Polymers are large molecules formed from the repeated linking of small molecules called monomers. Polymers are present in nature and can also be synthesized for use in many industrial applications. Some industrial polymers include plastics and foams....
1,5-Pentanediol (1,5-PDO) is a linear diol with an odd number of methylene groups. It is an important raw material for the synthesis of polyesters, unsaturated polyesters and polyurethanes. It can also be used to produce plastics, cosmetics and food. In addition, studies have shown that ...
Petroleum-based fossil fuels, such as gasoline, heating oil and diesel fuel, are commonly consumed for energy, but petroleum products aren’t used only as power sources. They're also used to create items like crayons, plastics, tires and even heart valves [source: Energy Information Administrati...
And, whether or not the packaging is of the appropriate size, several types of materials have traditionally been used for a single parcel: for example, tape, cardboard boxes, styrofoam padding and bubble wrap. Many of these packaging materials are composed of plastics. In fact, according to ...
it in the digestive systems of people from eight different countries.维也纳医科大学的一项小型试验在来自八个不同国家的人的消化系统中发现了这种物质的微小碎片;第一段最后一句So it shouldn't be all that surprising that humans are now apparently eating plastic.所以现在人类明显在吃塑料也就不足为奇了。
Join millions of self-starters in getting business resources, tips, and inspiring stories in your inbox. Email here Subscribe Subscribe Unsubscribe anytime. By entering your email, you agree to receive marketing emails from Shopify. By proceeding, you agree to theTerms and ConditionsandPrivacy Polic...
Warming-up What Are Substances Composed of? The theory of four elements As recently as a few thousand years ago,western scientists considered the whole earth to be made of 4 elements:Earth,Air,Fire,and Water.Air was the underlined element:this single substance made up everything in the world...