3的正整数次幂：3¹=3，3²=9，3³=27，3⁴=81，3⁵=243，3⁶=729，3⁷=2187，3⁸=6561…观察归纳，可得3²⁰⁰⁷的个位数字是（   ）

完形填空

    I like English very much. I think English is very important and 1. Here are my opinions of 2English well.

    I think there are many ways 3learn English. For example, asking the teacher 4 help is very helpful. One of my good 5said he had trouble 6English. His 7 English is very poor. So he reads aloud every morning. Now he can speak English very well. Watching English shows on TV can also be helpful. You can learn many words 8them. Remember "Where there is a 9, there is a way." Believe you can do it 10 .

化学用语是化学学科的专用语言，是我们学习化学的重要工具。请你从给定化合价的五种元素中，选择适当的元素，按要求写出相应物质的化学式(每空只填一种物质)：单质  ____ ；金属氧化物____ ；可作为复合肥料的盐____  。

2013年3月，******首次出访的国家中，既跨两大洲又跨东西半球的是（   ）