对职位的要求和规范作出详细、明确描述的文本是（）A、招聘广告B、工作说明书C、工作描

380/220V系统的三相四线制，中线截面为相线的（）

A.0.5倍

B.1倍

C.2倍

D.3倍

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).

（12分）如图，西藏是祖国大家庭中不可缺少的一员。仔细阅读下列有关西藏问题的材料，回答问题：

材料一：1951年5月23日西藏地方政府全权代表和中央人民政府全权代表在北京签订《关于和平解放西藏办法的协议》。

（1）材料一反映了那一历史事件？（2分）当时西藏地方政府全权代表中的首席代表是谁？（1分）

（2）这一事件有何意义？（2分）

材料二：西藏自治区乃东县人大代表索朗顿珠说：“1959年西藏民主改革后，我家和西藏百万农奴一样翻身得解放，享有充分的政治经济权利。……克松村现有202户、1700人，每户都盖了新房，每两户就有一部手扶拖拉机，全村还有100台小型收割机、播种机、脱粒机等机器设备，基本实现了农业机械化。”

（3）索朗顿珠所说“民主改革”使西藏发生了怎样的变化？（3分）

（4）材料二反映的现象是中央人民政府实行了什么政策的体现？（2分）藏民“享有充分的政治经济权利”是我国实施的哪一制度得以保障的？（2分）

以下情况（），不得使用施工升降机：

A.施工升降机出现故障时

B.超过额定载重量时

C.遇到5级大风时

D.驱动电机表面结冰时

E.电缆表面结冰时

气相色谱在应用中有（）特点。

A.选择性高

B.分离效率高

C.灵敏度高

D.分析速度快