汽车前照灯主要由灯泡、配光镜和（）组成。 A.反光镜 B.反射镜 C.折光镜 D.配

中国是茶叶的故乡，传说在公元前2730年中国人就发现并种植茶树，并把茶叶用于医药。公元3—4世纪，茶叶逐渐作为饮料，到公元6—7世纪，饮茶的习惯遍及全国。唐代的陆羽(782—804年)所著的《茶经》是世界上最早的有关茶叶的著作。中国种茶技术首先传入日本，日本在公元810年以前不种茶。16世纪中叶，中国的茶又传到欧洲，但当时的欧洲人只是把它当成标本来保存。直到18世纪，欧洲人才开始把茶当作饮料。茶传入俄国是公元1600年，当时只是进口茶叶当饮料，后来俄国茶叶商人从中国带回茶种，请中国茶农传授种茶技术，俄国才有了自己的茶叶。1780年，制茶的方法传入印度，1893年传到斯里兰卡。
今天，中国仍然是世界上最大的茶叶生产国，茶园的面积占了世界的一半，茶叶产量占了世界的65%。

中国早在什么时候已经普遍有了饮茶的习惯？

A．公元前3—4世纪
B．公元前6—7世纪
C．公元3—4世纪
D．公元6—7世纪

超声检查发现一侧肾内局限占位病变，下列有助于提示肾脓肿的是（）。

A.患侧肾脏弥漫性或局限性增大

B.病灶边界模糊不清

C.病灶内血流不丰富

D.肾内正常结构受压移位

E.患侧肾脏活动度明显受限

Transportation Decision Transportation decision consists of the following parts: 1.Selection of the mode is determined by the consideration of distance,cargo weights,linkage,timing and other requirements.Generally speaking,rail has high fixed cost and the relatively low variable cost.It can move heavy,large quantity of cargo in the long distance.But,rail is disadvantaged because of the longer transit time and less frequent service than motor. Motor carriers such as truck companies offer door-to-door service,that is,the cargo can be shipped from the shipper＇swarehouse to the consignee＇s.Trucking fixed cost is the lowest of any carrier,because the equipment is fairly cheap and the motor carriers do not have to invest in the roads on which they run their operations.However,their variable costs are very high.Its expenses include two major components:firstly,the pick-up and delivery costs;secondly,there are gas or fuel costs,labor expenses and toll roads fees to be paid to highway and toll road operators Therefore,motor transport is good for cargo with small quantity to be shipped within short distances. Water is the predominant choice of transportation as it has the capacity to take greatest quantity,travel longest distance with lowest cost.Transport by sea accounts for 80% of in-ternational trade.The major expenses for water are expenses associated with investment and maintenance of the ships and terminals.For example,a 100000-ton container ship costs US$ 200 million.Terminal associated costs include harbor fees and the cost for loading and unloading the goods. Transport by air has the highest cost but it is fast with the lowest ratio of loss and dam-age.If you need to deliver an urgent order,there is little choice but by air. 2.Transport service provider is selected for its experiences,equipment,services and prices.Competitive in the transport industry usually drives the prices down and motivates for better services.A company also chooses its transport service provider because of its long-standing business relationship with certain shipping companies. 3.The alternative routing and scheduling is specific for motor only because railway and water have strict route and timetable.Motor has special advantage in terms of flexibility.It has the ability to load goods at greater frequency,travel through different routes and making deliveries to different loca-tions.Questions:

How is a transportation service provider selected？（）

A.By supplier.

B.Referral.

C.Customer demands.

D.Experiences and equipments.

(四)

[背景资料]

某工程项目建筑面积6200m²，地上12层，地下2层，采用框架一剪力墙结构体系。施工单位编制了单位工程施工组织设计，在施工平面图设计中依次考虑了如下几项工作：

(1)布置现场内的运输道路，因场地条件限制采用主干道和消防车道合一单向行驶，道路宽度为3.2m；

(2)确定起重机的位置，本工程采用一台有轨式塔吊，为方便运输，将塔吊安放在临现场大门一侧；

(3)确定仓库及加工场的位置；

(4)布置水电管线，其中沿距拟建房屋30m远的主干道路边每隔150m布置一个消火栓；

(5)布置临时房屋，并在项目经理部办公室的墙面上悬挂了“五牌”和“二图”；

(6)技术经济指标分析。

当该工程进行到第8层拆除钢模板时，将拆下的18根钢管(每根长4m)和扣件运到井字架的吊盘上，5名工人随吊盘一起从8层高处下落。此时，该机器的操作人员因事未归，一名刚刚招来两天的合同工开动了卷扬机，卷扬机下降过程中，钢丝绳突然折断，人随吊盘下落坠地，造成2人死亡，3人重伤。

问题：

施工现场安全事故的主要诱因包括哪几方面？分析这起安全事故的原因是什么？

2013年11月23日，我国宣布划设东海防空识别区。防空识别区是沿海国家或地区基于海防空防安全需要，在面向海洋方向上空划定的特定空域，实质是基于国防需要而划设的预警区域。这是我国在行使（）

A.自卫权

B.独立权

C.平等权

D.管辖权