化学就在我们身边，它与我们的生活息息相关．

（1）下列是家庭厨房的一些常用物品：A．大米  B．食盐   C．莱籽油   D．食醋  E．铁锅  F．食品保鲜膜．从其中选择适当的物品，回答有关问题：（用宇母填写）

①主要为我们提供糖类的食品是　____ ．

②主要由合金制作的物品是____ ．

（2）炒菜时，锅内热油着火，此时可用锅盖盖灭，其原理是____．

（3）在实验室小坤同学发现：盛氢氧化钠溶液的试剂瓶用橡皮塞，盛盐酸的试剂瓶用玻璃塞，对此他产生疑惑．课后査阅资料知道：玻璃中含有的少量二氧化硅（SiO₂）能与氢氧化钠（NaOH）反应，生成有粘性的硅酸钠（Na₂SiO₃），容易将瓶和塞粘在一起，很难开启．硅酸钠（Na₂SiO₃）中Si的化合价为____ ．

（4）一氧化碳与氢气在一定条件下，发生反应的化学方程式是：2CＯ+4H₂X+C₂H₅OH 则X的化学式为　____ ．

为了看图钉落地后钉尖着地的概率有多大，小明做了大量重复试验，发现钉尖着地的次数是实验总次数的40%，下列说法错误的是（　　）

根据句子意思,用括号中所给汉语提示或英语单词的适当形式填空.(每空一词)

①Moreover, China's development depends largely on the modernization of science and ____(技术).

②The hall is beautifully decorated with many lights ____(悬挂)from the ceiling.

③Our present challenge is to prevent the percentage of people who are out of jobs from____ (增加)sharply.

④The company is dropping the prices in order to win ____(优势) over its competitors.

⑤You always have to smile if you work in the ____ (serve) industry.

⑥The young artist remained____ (know) for many years until his works spoke for him.

⑦It's great of Yuan Longping to solve the problem of ____ (hungry) for many people.

⑧Driving during the rush hour is____ (tire).