（1）按系统命名法命名．

①有机物CH₃CH（C₂H₅）CH（CH₃）₂的名称是____ ．

②在有机物分子中若某一个碳原子连接4个不同的原子或基团，则这种碳原子称为“手性碳原子”． C₇H₁₆的同分异构体中具有“手性碳原子”的有　____ 种，写出其中一种的名称____ ．

（2）写出下列各种有机物的结构简式

①2，3﹣二甲基﹣4﹣乙基已烷　　

②支链只有一个乙基且式量最小的烷烃　____ 　．

    Eleven countries are building a great wall of trees across Africa. It is called the Great Green Wall. The aim is to bring life to the dry lands and help to fight the bad environment.

    The wall is 8, 000 kilometers long and 15 kilometers wide. It covers from Senegal in the west to Djibouti in the east, on the south of the Sahara Desert (撒哈拉沙漠). So far, Senegal has made the best progress by planting about 11,000,000 trees.

    Many years ago, there were few trees in that area and the winds used to be very strong. It was harmful to the fields. Also, there was little rain, so few plants could grow and many people went hungry. Since the tree planting project started, the trees have provided food for the local people and increased the wetness (湿度) of the air. Little by little, there appeared green fields for people to grow plant.

    The project which began in 2007 is supposed to cost a total of 8, 000, 000, 000 dollars. Many countries are trying their best to help to continue the planting. So we will be able to see the whole green wall across Africa in the near future!

近年来，某地通过编制《基层群众自治组织依法履行职责事项》和《基层群众自治组织协助政府工作事项》，建立新型社区治理模式，划清了政府“行政权力”和基层群众自治组织“自治权力”的界限，将社区组织的发展权、干部的考核权、财务的管理权等归还于民。这种社区治理模式（   ）。

①规范了政府行政行为，保证政府依法行政

②削弱政府对基层公共事务和公益事业的管理

③能够提高基层群众参与政治生活的能力

④保证了基层群众依法直接行使民主权利

Dear God,

    Now that I am no longer young. I have friends whose mothers have passed away. I have heard these sons and daughters say they never fully thanked their mothers until it was too late to tell them.

    I am blessed with the dear mother who is still alive. I appreciate her devotion more each day. My mother does not change, but I do. As I grow older and wiser, I realize what an extraordinary person she is. It's sad that I am unable to say these words in her presence, but they flow easily from my pen.

    How does a daughter begin to thank her mother for life itself? For the love, patience and just plain hard work that go into raising a child? For running after a toddler（学步儿童）, for understanding a moody teenager, and for tolerating a college student who knows everything? For wailing for the day when the daughter realizes what her mother really is?

    How does a grown woman thank a mother for continuing to be a mother? For being ready with advice when asked or remaining silent when it is needed? For not saying “I told you so.” when she could have voiced these words dozens of times? For being essentially herself－loving, thoughtful, patient and forgiving?

    I don't know how to thank her, dear God, except to bless her and live up to the example she has set. I pray that I will look as good in the eyes of my children as my mother looks in mine.

人类历史上的三次科技革命，改变了人们的生活方式，提高了人们的生活质量。下面的生活场景与第三次科技革命的发明创造相关的是(     )