性前期的

The stude announces that their changeable regular of the center of gravity level speed in supporting phase is falling in tne first cushioning phase. When their center of gravity's vertical lines pass their heels and their knee joints go on extended contraction ,their center of gravity level speed has extended .the reason is that their angles have passed the heels and their swinging legs' kenn joints have swinging the front of their bodies. Its power originates the swinging leg's forward active swinging and the decurtation contraction of hip joints 、ankles of the supporting legs.the swinging leg shows "the calf's active backward swinging"before its landing impact,the skill affects the loss of center of gravity level speed when the swinging leg lands.they enlarge their trunks' forward-landing impact phase ,it can decrease the center of gravity level speed's loss after landing and impel the center of gravity level speed to pass the supporting spot quickly.

两人缓冲阶段身体重心水平速度变化规律是在体前缓冲阶段呈下降趋势；当身体重心垂线超过脚后跟后，在膝关节继续缓冲做退让收缩的情况下身体重心水平速度开始加大，原因是踝关节在最大缓冲时身体重心已移过支撑面及摆动腿膝关节已做体前摆动，主要动力来源于摆动腿的积极前摆和支撑腿髋、踝关节的克制性收缩；在摆动腿下压着地前期是大腿积极下压小腿随大腿的积极下压顺势向前下滑摆，在摆动腿下压着地后期表现出"小腿积极回摆"技术，对减小着地时的水平速度损失、加大向前用力都有积极影响；适当加大摆动下压着地阶段躯干的前倾角度，有利于减少着地时相的速度损失和有利于身体重心较快的移过支撑点；缩小后蹬结束后的后伸动作幅度，有利于减小腾空时间。

Factors involved in the expression of IFN -αwere studied. These included multiplicity of infection, cell inoculation concertration and cell growth phase. The results show that lower mulitiplicity of infection (M01.4PFU/cell) is beneficial to IFN-α production.The optimal cell inoculation concentration was 〓 cells/flask. The high efficient replication of BmNPV-IFN-α and expression were also due to the proper inoculation time of BmNPV-IFN-α, which was at 48-60 house after cell passage.

研究结果表明，重组病毒感染复数的改变对α-干扰素的产量的影响是时限性的，在一定低感染复数时（Mo1.4PFU），α-干扰素的产量较高；对于重组病毒的复制，最适的细胞接种密度为3.6～7.0×〓细胞/瓶；在细胞指数生长前期（48～60小时）接种重组病毒，对于获得较高的重组病毒效价和α-干扰素的产量都是有利的。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷