语法填空

    Green is not always referring to the color. In some cases, it is the term used for environmental____(friend). If you've been expecting to replace your furniture, consider ____(go) green because green furniture offers many benefits. Here are a few tips to get you started on your hunt for the perfect eco-friendly furniture.

    First, green furniture isn't harmful____your health. Also its making process doesn't cause damage to the environment in any way. Besides, by using eco-friendly ____(product), you prevent global warming to some degree in your own way.

    The materials____are used in furniture are what make them green. Materials can be good for the environment ____ because they are renewable resources or they are all ____(nature). A lack of chemicals in furniture also____(mean) it is a better choice for the environment. It may be hard to imagine that a sofa or a table could actually be____green product, but they really can be depending on what they ____(make)of.

    Therefore, when you want to hunt for the perfect green furniture, you should choose the green materials.

一个样本由a，3，5，b构成，且a，b是方程x²﹣8x+5=0的两根，则该样本的平均值是____ 

As we know, his father is a very famous scientist in physics. But what you don't know is that he _______ as a farmer for five years.

    日本鸟取县是《名侦探柯南》的作者青山刚昌的故乡，鸟取沙丘位于鸟曲县，是日本最大的沙丘，东西长约16公里，南北宽约2.4公里。它是由飘落到千代川泥砂之上的火山灰堆积而成的山峰，天长日久经日本海的风吹浪击，并将沙子带到了岸上，历经10万年创作出来的大自然杰作。官方每年还会邀请来自世界各地的沙雕艺术家来这里创作。鸟取沙丘降水较多，适合草木生长。当地政府为了保护该“沙漠”下了很大力气。