The property,characteristics and risk of fixed price contract were analyzed,the limit of fixed price contract was discussed,the common disputation type of the fixed price contract was studied,and the path to prevent building engineering fixed price contract disputation was illustrated.

<Abstrcat>This study was conducted for fully understanding of variations of gutta-percha content characters in leaves from different variance-types, which aims to provide theoretical guidance for selections of valuable resources and effective utilization of Eucommia ulmoides Oliv.

Seventeen characteristics of sample trees including finalized leaf and tender shoot were observed and measured, routine analysis on variation types and cluster analysis were conducted.

The conclusions are as follows: there are many germplasm resources and variation types of Euonymus fortunei , wh.

【Objective】 The natural variations and variation types of fruit characters of Idesia polycarpa Maxim.

The plant morphological characteristics,biological characters,vegetative organ structure and the content of active components in the root of five variance types of Salvia miltiorrhiza were studied.