按照更新时限的长短，不属于灌区数据库的内容的是（）。A、静态_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

按照更新时限的长短，不属于灌区数据库的内容的是（）。

A、静态数据

B、动态数据

C、将来数据

D、实时数据

答案

参考答案：C

计算题

常温下，一种烷烃A和一种单烯烃B组成混合气。A或B分子中最多只含4个碳原子，且B分子的碳原子数比A分子多。将1 L该混合气充分燃烧，在同温同压下得2.5 LCO₂气体，推断原混合气中A和B所有可能的组合及其体积比

单项选择题

Artificial flowers are used for scientific as Well as for decorative purposes. They are made from (51) of materials, such as wax and glass, so skillfully that they can scarcely be (52) from natural flowers. In making such models, painstaking skill and artistry are called for, (53) thorough knowledge of plant structure. The (54) of glass flowers in the Botanical Museum of Harvard University is the most famous in North America and is widely known (55) the scientific world. (56) , there are several thousand models in colored glass, the work of two artist naturalists, Leopold Blalschka and his son Rudolph.
The intention was to have the collection (57) at least one member of each flower family native to the United States. (58) it was never completed, it contains more than seven hundred species representing 164 families of flowering plants. (59) detail of these is accurately reproduced in color and structure. The models are (60) n locked cases as they are too valuable and fragile for classroom use.

A．All

B．Every

C．Whole

D．None