bizarre       segregate        hierarchy      depletion     contaminate 作答时注意词形变化1. Human beings must seek immediate solutions for problems leading to the rapid 1) ________ of the Earth’s ozone layer.2. To make the bookshelves look more organized, the library has 2) __________ the oversized(太大的，过大的) books from others and put them on a separate shelf.3. The reasons for firing an employee are becoming 3) ________ in some  cases, for example, someone lost his job because of his weight.4. Food producers should do their best to make sure that food is not 4) _____________ with any poisonous organisms.5. If you want to be ranked higher in the 5)  _________ of  occupations, you have to equip yourself with more marketable skills.