题目

蜡烛(主要成分是石蜡)及其燃烧的探究。实验过程： （1） 一组的同学经过探究发现他们小组的蜡烛是：①白色圆柱形固体②有轻微的气味③质地较软④密度比水小⑤有可燃性⑥受热易熔化⑦燃烧的火焰分为三层：外焰、内焰、焰心，上述描述中属于蜡烛的物理性质的是(填序号)。 （2） 二组同学将一根木条放到蜡烛火焰中，2秒后取出，发现从焰心到外焰木条碳化程度逐渐增大，这说明。 （3） 三组同学对蜡烛燃烧的产物进行了探究 In 2006，the documentary（纪录片） Planet Earth took us all on an ______ journey. We went from deep caves to the rain forests and the deep blue sea. Now a new series, Our Planet, will show us different animals and the influence (影响) of man on_______Thanks _____the latest 4K video cameras, the documentary______ people a new look at nature. “People are able to better______themselves into the lives of the animals," Alastair Fothergill told BBC News. The documentary not only shows the earth's beauty in new detail (细节), but also reports _____ poor conditions. The producer said, “Our Planet is here to say, The planet is ______ , and we 're killing it. So cut that out.?” In one sad scene, hundreds of walruses(海象), half-blind when out of the water, fall down and die on the beach because of global warming. Of course, it's not all about sadness. The documentary also talks about ______stories, such as Siberian tigers and blue whales. The documentary just wants to ask more people _____our planet. “ ______we do in the next 20 years will decide the future for all life on Earth,” Attenborough said.【1】A.amazingB.amazedC.strangeD.special【2】A.naturalB.natureC.earthD.land【3】A.forB.ofC.toD.at【4】A.allowingB.allowedC.allowD.allows【5】A.getsB.getC.gettingD.got【6】A.it’sB.itsC.themD.their【7】A.deadB.diedC.dyingD.death【8】A.successfulB.successC.successfullyD.succeed【9】A.to protectB.protectionC.protectingD.protected【10】A.WhoB.WhichC.WhatD.How