【简答题】 如图所示, R 1 = 2R 2 ,R 2 = 2R 3 ,R 2 两端的电压为10V,则电源电动势E=_______(设电源内阻为零)。
【简答题】简述断层在油气藏形成和破坏中的作用,并说明断层封闭性与哪些因素有关。
【单选题】Which of the following statements correctly describes the relationship between the size of the deadweight loss and the amount of tax revenue as the size of a tax increases from a small tax to a medium...
A.
Both the size of the deadweight loss and tax revenue increase.
B.
The size of the deadweight loss increases, but the tax revenue decreases.
C.
The size of the deadweight loss increases, but the tax revenue first increases, then decreases.
D.
Both the size of the deadweight loss and tax revenue decrease.
【单选题】 如图所示电路中,电阻R为( )Ω。
【简答题】《关雎》是《风》之始也,也是《 诗 经》第一篇。古人把它冠于三百零五篇之首,说明对它评价很高。《史记·外戚世家》曾经记述说:“《易》基乾坤,《诗》始《关雎》,《书》美厘降......夫妇之际,人道之大伦也。”又《汉书·匡衡传》记载匡衡疏云:“匹配之际,生民之始,万福之原。婚姻之礼正,然后品物遂而天命全。孔子论《诗》,一般都是以《关雎》为始。......此纲纪之首,王教之端也。”他们的着眼点是迂腐的...
【单选题】新华社1999年11月17日电,在兰州召开的一次能源地质国际研讨会传出讯息:“可燃冰”将帮助人类摆脱日益临近的能源危机。“可燃冰”是水与天然气相互作用形成的晶体物质,主要存在于冻土层和海底大陆坡中;据测定每0.1m 3 固体“可燃冰”可释放出20m 3 的甲烷气体。由此可判断下列说法中不正确的是 [ ]
【单选题】What is a 'progressive tax'? A 'progressive tax' is the tax ______.
A.
collected for social progress
B.
that increases with each passing year
C.
that is collected from those who earn most
D.
that varies (变化) according to how much money a person earns