在“乙醇、金刚石、稀有气体、二氧化锰、二氧化碳”中选用适当的物质填空。
（1）可充入灯泡作保护气的是____； （2）可用作燃料的是____；（3）可导致温室效应的是____；      （4）可制作玻璃刀的是____；（5）可用作实验室制氧气的催化剂的是____。

    Once there was a cowboy, Niulang,____lived with his elder brother and sister-in-law. But she disliked and abused him, and the boy was forced ____ (leave) home with only an old cow for company.

    The cow, however, was a former god who had broken royal rules and ____ (send) to earth in bovine（牛的）form.

    One day the cow led Niulang____a lake where fairies took a bath on earth. Among them was Zhinu____most beautiful fairy and a skilled woman tailor.

    The two fell in love at first sight and were soon married. They had a son and a daughter and their happy life was held up as an example for hundreds of ____ (year) in China. Yet in the eyes of the Jade Emperor, the Supreme Deity in Taoism, marriage between a mortal and fairy was____(strict) forbidden. He ordered the heaven troop to catch Zhinu back.

    Niulang grew desperate when he discovered Zhinu had been taken back to heaven____ (drive) by Niulang's misery, the cow told him to turn its hide into a pair of shoes after it died. The magic shoes whisked（匆匆带走）Niulang,____ (carry) his two children in baskets strung from a shoulder pole, off on a chase after the empress. Even the Jade Emperor was touched, and allowed Niulang and Zhinu to meet once a year on the____ (seven) night of the seventh month.

全部哲学，特别是近代哲学的基本问题，是思维和存在的关系问题，这是因为思维和存在的关系问题（    ）

已知函数$y=a^{x-1}(a>0,a\ne 1)$的图象恒过定点，若点在一次函数$y=mx+n$的图象上，其中$m,n>0,\frac{1}{m}+\frac{1}{n}$的最小值为（   ）