实现世贸组织目标的重要途径为（）A、经济全球化 B、可持续发展 C、贸易自由化 D、市场经

空气中含量最多的物质是 [ ]

A. 氧气

B. 氮气

C. 水蒸气

D. 二氧化碳

我国中医上常用“拔火罐”治疗病痛。“拔火罐”时将一蘸有酒精的棉球点燃放入广口罐中，片刻后取出棉球，迅速将罐倒扣在病患处，罐就牢牢的吸在皮肤上。这是由于罐内的气体压强      外界大气压（选填“大于”、“等于”或“小于”）。若拔10个火罐共消耗酒精14g，则其完全燃烧产生的热量能使       kg的水温度升高20℃（不计热量损失）。[酒精的热值为3.0×10⁷J/kg、水的比热容为4.2×10³ J/（kg·℃）]。请你写出酒精燃烧的化学方程式：                                。

某跨国纳税人国内外总所得10万美元，其中，来源于来源地国的所得为3万美元，来源于居住国本国的所得7万美元。收入来源地国实行30％的比例税率；居住国实行累进税率，10万美元的适用税率为40％；7万美元的适用税率为35％；

3万美元的适用税率为25％，按全额抵免法，该跨国纳税人应纳税额共计应为多少?

Research on animal intelligence always makes us wonder just how smart humans are. (1) the fruit-fly experiments described by Carl Zimmer in the Science Times. Fruit flies who were taught to be smarter than the average fruit fly (2) to live shorter lives. This suggests that (3) bulbs burn longer, that there is a(n) (4) in not being too bright.

Intelligence, it (5) , is a high-priced option. It takes more upkeep, burns more fuel and is slow (6) the starting line because it depends on learning — a(n) (7) process — instead of instinct. Plenty of other species are able to learn, and one of the things they’ve apparently learned is when to (8) .

Is there an adaptive value to (9) intelligence That’s the question behind this new research. Instead of casting a wistful glance (10) at all the species we’ve left in the dust I.Q.-wise, it implicitly asks what the real (11) of our own intelligence might be. This is (12) the mind of every animal we’ve ever met.

Research on animal intelligence also makes us wonder what experiments animals would (13) on humans if they had the chance. Every cat with an owner, (14) , is running a small-scale study in operant conditioning. We believe that (15) animals ran the labs, they would test us to (16) the limits of our patience, our faithfulness, our memory for locations. They would try to decide what intelligence in humans is really (17) , not merely how much of it there is. (18) , they would hope to study a(n) (19) question: Are humans actually aware of the world they live in (20) the results are inconclusive.

3（）

A.thinner

B.stabler

C.lighter

D.dimmer

语音信道的频率范围为300～3400Hz，如果采用PCM编码技术，则采样频率必须大于______。

A．300Hz
B．3400Hz
C．4000Hz
D．6800Hz