prior period
5.Statistical analysis on climatic general situation, the main circulation features and circulation evolution feature of cool dews wind weather in the earlier or later period in Guangxi indicate that subtropical high is weak, the Indochina trough is strong, polar vortex and eastern Asia trough are more western-wards than normal in the prior period in earlier years, it is sustained negative anomalies in each main subtropical high field.
10.Experiment 2, The PassageTime of Food from the Alimentary Tract of Ducks. 48 adult Peking drakes were used to study optimal starvation time prior to force feeding and excreta collection period , basing on the passage time of food through the alimentary tract of drake which is confirmed by excreta and feed residues in alimentary tract.

