气相色谱法测定水中有机磷浓药时，新填充的色谱柱在老化过程中应注入较高浓度的有机磷农药

内衬上皮类似于缩余釉上皮、由2～4层扁平细胞或立方细胞构成的囊肿为（）

A.牙源性角化囊肿

B.鼻唇囊肿

C.含牙囊肿

D.黏液囊肿

E.牙源性钙化囊肿

如图示：经纬仪在O点以O①边为后视（0°00′00″），用极坐标法测设①、②、③、④、⑤各点位置，在表中填出各点的直角坐标，并据此计算出各点的极坐标及相邻点间距。

患儿男，8岁。自幼就比同龄小孩发育慢些，2岁才会走路，会叫爸妈，目前只会讲简单的句子，基本上仅用于表达要求，如"要吃饭"、"妈妈走"，不会进行简单的交流，不会和其他小朋友玩，不会玩玩具。吃饭、大小便不能完全自理，需要家人协助。勉强呆在幼儿园，老师反映患儿什么都学不会，且手脚总动个不停，注意力不集中，上课时满地跑，有时用头撞墙。查体：患者眼眶距宽，两眼外角上斜，内眦赘皮，鼻梁低，通贯掌。精神状况检查：患儿在诊室里手脚动个不停，只会从一数到三，不认识颜色，会用积木搭四层塔，对部分指令不理解，会讲简单的词，不时傻笑，语谈间突发冲动，用头撞墙。

此患儿需要考虑以下哪些诊断（）。

A.儿童孤独症

B.脆性X染色体综合征

C.儿童脑器质性精神障碍

D.Turner综合征

E.苯丙酮尿症

F.精神分裂症

G.Down综合征

H.Asperger综合征

具有降血脂作用的成分是（）

A.葛根素

B.桂皮酸

C.柴胡挥发油

D.麻黄挥发油

E.柴胡多糖

There (1) not one type of reading but several according to your reasons for reading. To read carefully, you have to (2) your reading speed and technique (3) your aim (4) reading. Skimming is a technique necessary for quick and efficient reading.

When skimming, you (5) the reading (6) quickly in order to get the (7) of it, to know how it is organized, (8) an idea of the tone or the intention of the writer. Skimming is (9) an activity which (10) an overall view of the text and (11) a definite reading competence.

Skimming doesn’t need reading all the material, but it doesn’t mean that it is an (12) skill for the lazy, because it need a high degree of alertness and concentration.

When you read, you usually start with (13) understanding and move towards detailed understanding rather than working the other way round. But (14) is also used after you have already carefully studied and you need to (15) the major ideas and concepts.

In order to be able to skim quickly and (16) through a text, you should know where to look for what you want. In preview skimming you read the introductory information, the headings and subheadings, and the summary, if one is provided. (17) this skimming, decide whether to read the material more thoroughly, and select the appropriate speed (18) you read.

The same procedure (19) for preview skimming could also be used to get an overview. Another method would be to read only key words. This is done by omitting the unnecessary words, phrases, and sentences.

In order to skim efficiently and fulfill your purpose, (20) practice is necessary.

7().

A.fist

B.hist

C.gist

D.list