一根5类以太网线内总共包含（）对线，实际使用中最多用到（）对线。

Mr. White is a careful and experienced engineer, so he is often        to finish some challenging tasks.

A．appreciated

B．approached

C．appointed

D．agreed

某课外活动小组用如图装置进行实验，试回答下列问题。

(1)若开始时开关K与a连接，则B极的电极反应式为________________。

(2)若开始时开关K与b连接，则B 极的电极反应式为____________________，总反应的离子方程式为

___________________有关上述实验，下列说法正确的是（填序号）__________。

①溶液中Na⁺向A极移动

②从A极处逸出的气体能使湿润的KI淀粉试纸变蓝

③反应一段时间后加适量盐酸可恢复到电解前电解质的浓度

④若标准状况下B极产生2. 24 L气体，则溶液中转移0.2 mol电子

(3)该小组同学认为，如果模拟工业上离子交换膜法制烧碱的方法，那么可以设想用如图装置电解硫酸钾 溶液来制取氢气、氧气、硫酸和氢氧化钾。

①该电解槽的阳极反应式为_________________。此时通过阴离子交换膜的离子数_____（填“大于”、“小于”或“等于”）通过阳离子交换膜的离子数。

②制得的氢氧化钾溶液从出口（填写“A”、“B”、 “C”或“D”）____导出。

③通电开始后，阴极附近溶液pH会增大，请简述原因_______________________。

④若将制得的氢气、氧气和氢氧化钾溶液组合为氢氧燃料电池，则电池正极的电极反应式为________。

建设项目的环境影响报告书，必须对建设项目可能产生的大气污染和对生态环境的影响作出评价，规定防治措施，并按照规定的程序报（）审查批准。

A.地方政府主管领导

B.大气污染防治监管部门

C.建设单位主管领导

D.环境保护行政主管部门

Research on animal intelligence always makes me wonder just how smart humans are. (51) the fruit-fly experiments described in Carl Zimmer’s piece in the Science Times on Tuesday. Fruit flies who were taught to be smarter than the average fruit fly (52) to live shorter lives. This suggests that (53) bulbs burn longer, that there is an advantage in not being too terrifically bright.

Intelligence, it (54) , is a high-priced option. It takes more upkeep, burns more fuel and is slow off the starting line because it depends on learning—a (55) process—instead of instinct. Plenty of other species are able to learn, and one of the things they’ve apparently learned is when to (56) .

Is there an adaptive value to (57) intelligence That’s the question behind this new research. I like it. Instead of casting a wistful glance (58) at all the species we’ve left in the dust I.Q.-wise, it implicitly asks what the real (59) of our own intelligence might be. This is on the mind of every animal I’ve ever met.

Research on animal intelligence also makes me wonder what experiments animals would (60) on humans if they had the chance.

54().

A. insists on

B. sums up

C. turns out

D. puts forward

豚草是原产自北美的植物，其花粉是北京地区主要的过敏原。下图甲表示我国北安河地区路旁的一片闲散地，课外小组的同学对此地部分植物的种群密度连续进行了五年的调查，结果如表所示（单位：株／m2）

采用的调查方法是（）；取样的关键除应考虑样方的大小和数量外，还应注意（）；种群密度的计算方法是取所有样方内株数的（）。