某地1990年6月30日有男性人口13697600人，男性人口中因心血管疾病死亡18311人，其中因冠心病死亡654人，计算该地男性人口冠心病死亡强度

A:654／13697600×100000/10万=4.77/10万 B:654/18311×100%=3.57% C:18311/13697600×1000‰=1.34‰ D:654／13697600×100%=0.00477% E:资料不全，无法计算

山莨菪碱(654-2)（　）

A:抑制细胞内磷酸二酯酶，减慢c-AMP的分解 B:β受体兴奋剂 C:保护肥大细胞或嗜碱粒细胞膜作用，减少生物活性物质的释放 D:减少c-GMP浓度，使生物活性物质释放减少 E:提高腺苷环化酶和抑制磷酸二酯酶，稳定细胞溶酶体

为减轻桥体所承受的力而采取的措施中无效的是（）。

A:减小桥体颊舌径宽度 B:面添加副沟、加深颊舌沟 C:加厚桥体金属层 D:扩大桥体与固位体之间舌外展隙 E:降低非功能尖斜度

ITU-T已规范了4种类型的单模光纤，即G.652光纤、G.653光纤、G.654光纤和G.655光纤。接入光缆网中常用（）。

A:G.652光纤 B:G.653光纤 C:G.654光纤 D:G.655光纤

光传输使用的光纤目前常见的有G.652、G.653、G.654和G.655，下列描述错误的是（）。

A:我国大量铺设的为G.652光纤 B:都是单模光纤 C:最适合波分使用的是G.655光纤 D:G.653和G.654光纤没有商用价值

解痉药654-2是指

A:天然的山莨菪碱 B:人工合成的山莨菪碱 C:天然的东莨菪碱 D:人工合成的东莨菪碱 E:人工合成的丁溴东莨菪碱

[ With the 4G telecommunications systems now starting to be deployed, people are looking towards the development of 5th generation or 5G technology services. Although the deployment of any wireless or cellular system take many years, development of the 5G technology systems is being investigated. The new 5G technologies will need to be chosen developed and perfected to enable timely and reliable deployment. The new 5th generation,5G technology for cellular systems will probably start to come to fruition around 2020. The current status of the 5G technology for cellular systems is very much in the early development stages. Many companies are looking into the technologies that could be used to become part of the system. In addition to this, a numberof universities have set up 5G research units focused on developing the technologies for 5G. In addition, the standards bodies, particularly 3GPP are aware of the development but are not actively planing the 5G systems yet. Many of the technologies to be used for 5G will start to appear in the systems used for 4G and then as the new 5G cellular system starts to formulate in a more concrete manner, they will be incorporated into the new 5G cellular system. The major issue with 5G technology is that there is such an enormously wide variation in the requirements：super fast downloads to small data requirements for IoT than any one system will not be able to meet these needs. Accordingly a layer approach is likely to be adopted. As one commentator stated：5G is not just a mobile technology. It is ubiquitous access to high & low data rate services.]

the major issue facing with 5G technology is( ).

A:super fast downloads B:small data requirements for IoT C:4G system has already satisfied these needs D:an enormously wide variation in the requirements