【单选题】下列对群落特点的表述中,说法正确的是 ( )
A.
群落内的各种生物都是偶然散布的、孤立的,相互之间不存在物质循环和能量转移的复杂联系
B.
在随时间变化的过程中,生物群落经常改变其外貌,并具有一定的顺序状态,即具有发展和演变的动态、特征
【多选题】身体出现热盛于内症状时可以采用()药膳达到清解作用?
【单选题】以下关于时间序列分析方法表述正确的是( )
A.
时间序列分析方法主要包括描述性时序分析和频域分析两大类。
B.
时域分析方法的分析步骤不包括考察观察值序列的特征。
C.
频域分析方法主要从序列自相关的角度揭示时间序列的发展规律。
D.
操作简单、直观有效是描述性时间序列分析方法的突出特点。
【单选题】At first it seemed that the building would be all right but later it was found to need______.
【简答题】C. Dictation Fill in the blanks in the following passage according to what you have just heard. Man has been polluting the Earth from the time he first made fire, washed his clothes in the river and t...
【单选题】At first it seemed that building would be all right but later it was found to need___.
【单选题】胸腔穿刺抽取一定液体后,患者出现持绫咳嗽,应该注意
A.
提示胸腔积液排放到一定程度,肺已开始复张,抽液需要慎重,必要时停止操作
【单选题】My mother passed the driving-test at her first attempt. It was all ______ she had been practicing so hard.