A:人民出版社首次披露,16年来作家贾平凹多次向中央申诉,他的作品《废都》终于被解禁,重见天日。
B:收集史料不容易,鉴定和运用史料更不容易,中国过去的大部分史学家主要力量就用在这方面。
C:如今的手机已不再是单纯的通信工具,因而成为人们生活的贴身伴侣,用来尽情表现个人品味。
D:个人住房转让营业税新政影响立竿见影,二手房交易量骤减二倍以上。
The word “day” has two meanings. When we talk about the number of days in a year, we are using “day” to mean 24 hours. But when we talk about day and night, we are using “day” to mean the time between sunrise and sunset. Since the earth looks like a ball, the sun can shine on only half of it at a time. Always one half of the earth is having day and the other half night. A place is moved from day into night and from night into day over and over by the spinning(旋转)of the earth. At the equator(赤道)day and night are sometimes the same length(长度). They are each twelve hours long. The sun rises at 6 o’clock in the morning and sets at 6 o’clock in the evening. For six months the North Pole is tilted(倾斜)toward the sun. In those months the Northern Hemisphere(半球)gets more hours of sunlight than the Southern Hemisphere. Days are longer than nights. South of the equator nights are longer than days. For the other six months the North Pole is tilted away from the sun. Then the Southern Hemisphere gets more sunlight. Days are longer than nights. North of the equator nights are longer than days. Winter is the season of long nights. Summer is the season of long days.
科学探究要应用多种多样的科学方法,下列描述中哪项不是科学方法?( )
设集合M=x|x2-x-6<0,N=x|y=log2x-1,则M∩N等于( )