搜题请搜索小程序“爱下问搜题”
问题 解答题
己知f（x）=log2（x+1），当点（x，y）在函数y=f（x）的图象上时，点(
x
3
 ，
y
2
)在函数y=g（x）的图象上．
（1）写出y=g（x）的解析式；
（2）求f（x）-g（x）=0方程的根．
答案

（1）依题意，

y=f(x)=log2(x+1)
y
2
=g(
x
3
)
则g(
x
3
)=
1
2
log2(x+1)故g(x)=
1
2
log2(3x+1)

（2）由f（x）-g（x）=0得，log2(x+1)=

1
2
log2(3x+1)∴
x+1＞0
3x+1＞0
3x+1=(x+1)2
解得，x=0或x=1

完形填空
Did you feel it was warmer than before?
“There have been twenty-one    winters in China since 1986,” said scientists. “          the past 100 years, as the world temperature has been up by 0.74 °C , the temperature in North China has       1.4 °C in only 50 years.”
China needs to take quick actions to         carbon dioxide (二氧化碳) emission (排放) because it’s the main reason for world warming. The good news is that China has seen the importance of going       China sets the goal of cutting energy use by 20% and pollution emission by 10% in the 11th          Plan.
Here is some advice for you.
Wearing used clothes such as your brother’s, sister’s or dad’s old T-shirts means you         energy; And don’t forget       the lights when you leave a room and turn off your television and computer when they are not               ! Besides, taking a bus saves a lot of oil every year. Also open a window and try not to use the air conditioner (空调). If necessary, set the temperature       in summer and lower in winter to save energy; It isn’t good to use paper cups, bags or boxes in our daily life.
小题1:
A．coolB．hotC．coldD．warm
小题2:
A．duringB．forC．sinceD．after
小题3:
A．climbedB．wentC．arrivedD．got
小题4:
A．increaseB．improveC．cutD．break
小题5:
A．yellowB．greenC．blackD．blue
小题6:
A．Five-YearB．Five--YearsC．five yearsD．five year
小题7:
A．useB．findC．saveD．keep
小题8:
A．to turn onB．to turn offC．to turn upD．to turn over
小题9:
A．in useB．on businessC．at presentD．for fun
小题10:
A．strongerB．higherC．tallerD．quicker
查看答案
实验题

聚合氯化铝是一种新型、高效絮凝剂和净水剂，其单体是液态的碱式氯化铝[Al2(OH)nCl6-n]。本实验采用铝盐溶液水解絮凝法制备碱式氯化铝。其制备原料为分布广、价格廉的高岭土，化学组成为：Al2O3（25%～34%）、SiO2（40%～50%）、Fe2O3（0．5%～3．0%）以及少量杂质和水分。已知氧化铝有多种不同的结构，化学性质也有差异，且一定条件下可相互转化；高岭土中的氧化铝难溶于酸。制备碱式氯化铝的实验流程如下：

已知：Fe3＋、Al3＋以氢氧化物形式完全沉淀时，溶液的pH分别为3.2、5.2。

根据流程图回答下列问题：

（1）“煅烧”的目的是______________________。

（2）“浸出”过程中发生反应的离子方程式为_________________________。

（3）“浸出”选用的酸为_______。配制质量分数15％的A酸需要200mL30％的A酸（密度约为1.15g/cm3）和_______g蒸馏水，配制用到的仪器有烧杯、玻璃棒、___________。

（4）为提高铝的浸出率，可采取的措施有_______________（要求写出三条）。

（5）“调节溶液pH在4．2～4．5”的过程中，除添加必要的试剂，还需借助的实验用品是_________________；“蒸发浓缩”需保持温度在90～100℃，控制温度的实验方法是_________________。

（6）实验中制备碱式氯化铝反应的化学方程式为_________________

查看答案