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问题 选择题

市场上经常见锂离子电池，它的负极材料是金属锂和碳的复合材料（碳作为金属锂的载体），电解质为一种能传导Li+的高分子材料。这种锂离子电池的电池反应式为：

Li + 2Li0.35NiO22Li0.5NiO2。下列说法不正确的是                 （    ）

A．放电时，负极的电极反应式：Li — e-＝ Li+

B．该电池不能用水溶液作为电解质

C．充电时，Li0.5NiO2既发生氧化反应又发生还原反应

D．放电过程中Li+向负极移动

答案

答案：D

放电相当于原电池，充电相当于电解池。在原电池中负极失去电子，发生氧化反应，正极得到电子发生还原反应，所以AC正确。锂属于活泼金属异和水反应，所以电解质不能用水溶液，B正确。在原电池电子通过导线传递到正极上，所以溶液中的阳离子向正极移动，D不正确。答案D。

填空题


A How to Use a Painting Knife 使用画刀的方法
Painting with a knife is a bit like putting butter on bread and produces quite a (1) result to a brush. Painting knives are excellent for producing textured, impasto work and (2) areas of flat colour.
What’s the difference between a palette knife and a painting knife
A palette knife is a long, straight spatula that is used (3) mixing paints and scraping a palette clean. They’re made from metal, plastic, or wood and (4) either be completely straight or have a slightly bent handle. A painting knife has (5) large crank in the handle, which takes your hand away from the painting surface. They (6) in numerous shapes(for example pear-, diamond-, or trowel-shaped) and are used for painting (7) of a brush. The edge of the knife is blunt, so that it doesn’t cut the (8) .
·What shape of painting knife should I use
Different shaped painting knives produce different effects. For example, a short blade produces angular strokes (9)a long blade makes it easy to put down sweeps of colour.
·Why can’t I use a palette knife to paint with
You can. Painting (10) just have the advantage of coming in more angular shapes and with sharper points. And (11) larger crank in the handle means there’s less chance of rubbing your knuckles into wet (12) . If you’re unsure whether you’re going to enjoy painting with a knife, first buy a (13) , plastic palette knife and experiment a bit with this before upgrading to a wood-and-metal knife.
·How do I use painting knife
(14) the handle firmly so you’re got good control. Pick up some paint off your palette (15) the tip, as you’d pick up some butter with a knife. Use the side of the (16) to spread paint across your canvas, or press it onto the canvas, as you (17) spread butter across a slice of bread．It’ll seem strange at first as it’s quite (18) to using a brush. Using just the tip of the blade will produce small dots. (19) the edge of the knife down will produce fine lines. Pressing the blade flat down (20) the paint will produce ridges. Scrape back into the paint to reveal underlying layers (called sgraffito).

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单项选择题 A1/A2型题

维生素B2的重要生理功能不包括（）。

A.防止口角炎

B.防止舌炎

C.防止癞皮病

D.防止角膜炎

E.防止脂溢性皮炎
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