紫外线杀菌的最佳波长为（）。 A.200nm B.265nm C.300nm D.5 发布时间：2017-05-21 11:57 │ 来源：www.tikuol.com 题型：单项选择题 A1/A2型题 问题： 紫外线杀菌的最佳波长为（）。A.200nmB.265nmC.300nmD.560nmE.650nm
题型：单项选择题 A1/A2型题 Different types of maps have different uses.Tourist maps, for example, have signs to show places of interest in an area. When tourists read these maps, it is easy for them to find where to go and what to see in a place and it is easy for them to go and find their ways to these places. Road maps show large areas so that people can plan long journeys. Different types of roads are given different numbers. For example, if you want to go to Wood Green, you just follow No. 621 Road and keep looking at the road signs. Distribution maps (分布图) use colors or signs to show facts about an area. For example, where different languages are spoken, how many people live in an area, how cold and hot some places are, or whether a place is short of water.Some maps, such as railway maps, use straightlines to show everything. This is easy for people to read. Trains are fast. People don’t have to think about small places they go past. They just need to know the two ends of their trips.小题1:Jim is going to Beijing Zoo. Which map does he need most?A．A tourist map.B．A road map.C．A distribution map.D．A railway map.小题2:How can you tell different roads on road maps?A．By using different colors.B．By finding the numbers.C．By following No. 621 Road.D．By looking at the road signs.小题3:Why do railway maps use straight lines?A．Because railways are straight.B．Because people like straight lines.C．Because people can read them easily.D．Because railways have only two ends. 查看答案
题型：单项选择题 A1/A2型题 患者，男，15岁，左小腿近端疼痛半年余。局部软组织隆起，质硬、皮温较高。X线片示腿骨干骺端均匀性致密呈象牙样及棉絮状，骨膜反应不明显，应考虑（）A.骨纤维异常增殖症B.硬化性骨髓炎C.软骨母细胞瘤D.内生软骨瘤E.成骨型骨肉瘤 查看答案
题型：单项选择题 A1/A2型题 一个口袋中有15个黑球和若干个白球，从口袋中一次摸出10个球，求出黑球数与10的比值，不断重复上述过程，总共摸了10次，黑球数与10的比值的平均数为1/5，因此可估计口袋中大约有______个白球． 查看答案
