问题
单项选择题
343，5，
，1，（）。
A．1
B．-1
C．0
D．4
答案
参考答案：B
解析：
343=73：7(7-4)，5=51=5(5-4)，=3-1=3(3-4)，1=1-3=1(1-4)。底数构成公差为-2的等差数列，指数为底数减去4，由此可知下一项应为(-1)(-1-4)=(-1)-5-1，故选B。
搜题请搜索小程序“爱下问搜题”
343，5，，1，（）。
A．1
B．-1
C．0
D．4
参考答案：B
解析：
343=73：7(7-4)，5=51=5(5-4)，=3-1=3(3-4)，1=1-3=1(1-4)。底数构成公差为-2的等差数列，指数为底数减去4，由此可知下一项应为(-1)(-1-4)=(-1)-5-1，故选B。
| 阅读理解。 | ||||||||||||||||
| Some birthday customs are quite similar in many parts of the world---- birthday candles (蜡烛), birthday games，and birthday cakes. But some customs are more specific to certain countries. Here are some children talking about their customs. Linda---I am fourteen. I come from Aruba. In our country, Children take something special to school for their classmates and all teachers. Each teacher gives the birthday child a small gift like a pencil, an eraser or a postcard. The birthday child is also allowed to wear special clothes instead of the school uniform. Lucy---I am one year older than Linda. Denmark is my country. A flag is flown outside a window to show that someone who lives in that house is having a birthday. Presents are placed around the child's bed while they are sleeping so they will see them at once when they wake up. Tom---I am as old as Linda. I am from Brazil. The birthday child receives a pull on the earlobe (耳垂) for each year in my country. The birthday person also gives the first slice of cake to his/her most special friend or relative, usually mom or dad. | ||||||||||||||||
|