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如图甲所示电路中，D为晶体二极管（正向电阻为O，反向电阻为无穷大），R₁=R₂=4Ω，R₃=6Ω，当在AB间加上如图乙所示的交变电压时，求：

（1）在0～1×10^-2s时间内通过R₁的电流．

（2）1s内电阻R₃所消耗的电能．

痛痹的临床特征是（）

A.关节酸痛，游走不定

B.关节疼痛，红肿灼热

C.疼痛剧烈，痛有定处

D.酸痛重者，肌肤不仁

E.屈伸不利，心悸气短

2011年11月28日，联合国气候变化大会在图中甲城市召开。甲城市的气候资料如图所示。据此完成题。

小题1:关于甲城气候特点及其成因的叙述，正确的有

A．气温年较差大，受海陆热力差异影响

B．气温年较差小，纬度低且受暖流影响

C．冬季降水丰沛，受信风和地形的影响

D．夏季降水稀少，受副高和西风带控制小题2:与甲城地区相比，乙城地区

A．水热配置条件好，有利于农作物的生长

B．副热带高压带南移该地，1月降水较少

C．受副热带高气压带影响，7月气温较高

D．受到东南信风影响，港口附近风浪较大

频率联络线功率偏差控制TBC

Most geologists believe oil results from chemical transformations of hydrocarbons derived from organisms buried under ancient seas. Suppose, instead, that oil actually results from bacterial action on other complex hydrocarbons that are trapped within the Earth. As is well known, the volume of these hydrocarbons exceeds that of buried organisms. Therefore, our oil reserves would be greater than most geologists believe.
Which of the following, if true, gives the pest support to the argument above about our oil reserves

A．Most geologists think optimistically about the Earth’s reserves of oil.

B．Most geologists have performed accurate chemical analyses on previously discovered oil reserves.

C．Ancient seas are buried within the Earth at many places where fossils are abundant.

D．The only bacteria yet found in oil reserves could have leaked down drill holes from surface contaminants.

E．(E) Chemical transformations reduce the volume of buried hydrocarbons derived from organisms by roughly the same proportion as bacterial action reduces the volume of other complex hydrocarbons.