夏天，宾馆的厨师常常把许多做好的菜肴用保鲜膜盖好，放在冰箱里冷藏，这样做的目的是（    ）

写出反义词

普通—____   茂密—____   寒冷—____

埃博拉病毒属于丝状包膜病毒，其基本结构如图所示，病毒传染性强，2014年非洲埃博拉病毒出血热的感染及死亡人数都达到历史最高．下列有关埃博拉病毒的叙述中，正确的是（　　）

①A结构是在宿主细胞的核糖体上合成的

②C结构的成分是磷脂双分子层

③B结构在噬菌体上不存在

④在疾病传播时埃博拉病毒属于传染源

⑤在实验室中可用牛肉膏蛋白胨培养基培养病毒用于科学研究．

    Jadav Payeng is a forestry worker from Jorhat, India. Over the past 38 years, he has planted trees on a sandbar (沙洲) of the Brahmaputra River and has1 it into a forest. One day in 1979, 16-year-old Payeng was walking

    2 the bank of the Brahmaputra River. He saw many snakes on the sandbars. These snakes died in a few days' time

    3the heat and the absence (缺失) of trees. Payeng felt very4when he saw this. He decided to plant some trees. Single-handedly, he started planting bamboo trees, as only bamboo trees could survive (存活) in the sandbars.

    To water the trees was a difficult5for one man. With his hard work and great effort, day by day the6 bamboo trees grew into a forest. His tree planting has changed the soil (土壤). Now the sandbar is a thick forest and7 to thousands of plants and animals. A large group of around 100 elephants visit the forest every year and8 there for a few months.

    Payeng is now in9ifties. He has planted close to 1,400 acres (英亩) of forests and is 10 as the Forest Man of India. In 2015, he was honored with Padma Shri, one of the top awards (奖) in India.