The ephemerals is a kind of plant starting its new living period using the melting snow water in the early spring . they make use of melting snow water and spring rainwater under certain temperature to grow , then they will finish the life history quickly before hot summer comes 早春短命植物是一类生长在干旱区，以早春融雪水启动其新的生活周期，利用融雪水及春季雨水提供的土壤湿度和一定的温度生长发育，在炎热夏季来临之前迅速完成生活史的一年生草本植物。
The studies or designs about housing which start from the number of family members , often ignore different characters in different families and different requirements of every member ; then it ca n ' t adapt the life changing during the life cycle . to make the housing good applicability , we must do more studies about the characters of different family and it ' s dwelling space 以家庭人口数量为出发点的住宅设计、研究忽视了不同家庭类型的特点以及家庭成员个体的需求，不能适应由家庭生活周期、生活方式变化产生的各种需求，因此要使住宅具有长期良好的适用性能，必须针对不同的家庭类型进行深入细致的研究，同时对相应的住宅空间进行分析研究。
