常到的

The sources of pollution are as follows, 1,feces discharged from public washroom emit an unbearable naucious odor; 2、water discharged from factories is black and odorous, covered with floating waste 3、air emission from factories smells pungent and spreads to every corner,4、air emission from fertilizer factories contains dust,lead, and coal ash, and other particles harmful to health 5、grasslands and lawns in parks are covered with litters which are unhygenic and unsightly.

造成环境污染的污染源是：1、公共厕所排出的粪便散发出难闻的气味，让人恶心。2、工厂排出的废水又黑又臭，还浮着一些秽物。3、工厂排出的废气很刺鼻，会散发到小镇的各个角落。4、化肥厂排出的气体中含有粉尘、铅、煤灰等对人体有害的物质。5、公园的草坪上常有游人丢弃的垃圾，既不卫生，又影响市容。

Second, upgrade the quality of new flats have triggered war, the quality of real estate in the region have emerged from low-end to high-end change in the trend: Community planning has undergone a qualitative change, such as changing traditional第七街区1 community planning, the introduction of the concept of the European block, and build residential and commercial areas of the emerging separation block; architectural forms change, the change from the tower to the Floor, such as ZHUANG Garden 2,弘景oasis 2, Changan part of Metro real estate, green in the late Tadong 3 Floor, Cheng Chang Chong transformation projects, the proportion increased significantly Floor; regional construction signs beginning to emerge,第七街区of "fish" shaped commercial street and a four-star class hotel and residential construction shown by the neo-gothic architectural style will become the Southwest Sihuan landmarks.

第二，提高质量的新单位，引发战争的质量，房地产在该区域已出现从低端到高端的变化趋势：社区规划经历了一个质的变化，如改变传统第七街区1社区规划，引进的概念，欧洲块，建设住宅和商业领域的新兴分离块；建筑形式的变化，这种变化从塔在地上，如庄花园2 ，弘景绿洲2 ，长安新城的一部分，房地产，绿色后期塔东3楼，郑常庄改造项目，这一比例显着增加楼；区域建设的迹象开始出现，第七街区的&鱼&形商业街和一个四星级酒店和住宅建筑所表现出的新哥特式建筑风格，将成为西南四环标志。

First, the stations'timing process and the slot aligning are discussed. Second, the dissertation propose a resource request random access method based on feedback. The performances of this method are analyzed. Third, proceed from the considerations of the MAC protocol for the HFC system, a QOS-oriental scheduling algorithm for the MAC protocol based on dynamic TDMA is proposed. Simulation results show that the performance of this algorithm is better than that of the first come first service. Forth, two contention resolution algorithms ----p-persistent CRA and tree CRA, which are usually adopted in the HFC system, are summarized. The delay and characteristic are compared. At last, the dissertation introduces the function implementation of the MAC layer based on COM21 UPSTREAMS.

首先，讨论了基站的同步进程和时隙同步的实现；然后，本文提出了一种带反馈模块的资源申请信号随机接入方法，并对其进行性能分析；然后，从HFC系统的MAC协议出发，提出了一种用于基于动态TDMA技术的MAC协议的业务安排算法，计算机仿真结果表明其性能优于先到先服务法的性能；然后概述了常用于HFC系统的两种冲突解决算法——p-坚持冲突解决算法和树型冲突解决算法，比较两者的时延性能与特征；最后，介绍了基于COM21 UPSTREAMS协议的MAC层功能实现，给出了硬件框图和照片。

This practice is still retained among the wild and uncultivated nations that have never been formed into civil states, like the Tartars and others in the east; where the climate itself, and the boundless extent of their territory, conspire to retain them still in the same savage state of vagrant liberty, which was universal in the earliest ages; and which Tacitus informs us continued among the Germans till the decline of the Roman empire.7 We have also a striking example of the same kind in the history of Abraham and his nephew Lot.8 When their joint substance became so great, that pasture and other conveniences grew scarce, the natural consequence was that a strife arose between their servants; so that it was no longer practicable to dwell together.

这种行为方式仍然保留在那些野蛮无教养的未形成世俗政府的国家之中，比如鞑靼人和其他的东方人；在这些地方气候本身，以及他们领土的无边界性，共同促使他们仍然停留在漂泊自由的野人状态，这在最初的时代是普遍的情形；塔西特斯(56～120？)告诉我们杰曼人（German，常译为日尔曼，我不知道究竟是音译呢，还是意译，或许源于其它语言？）的这种状态一直保持到罗马帝国的衰落。这种情况，我们还有一个明显的例子，即历史上的亚伯拉罕和他的外甥罗得。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。