比例性

And rheumatic valves also accounted for 70 cases (88.5%) of aortic stenosis plus insufficiency. The rheumatic valves was decreased dramatically as the cause of the aortic valve disease, aortic root dilation and degenerative valves increased significantly, while others had no significant changes.

随着社会进步和人口老龄化，风湿性病因所占比例大幅下降，主动脉根部扩张导致的主动脉关闭不全有较大幅度的上升，退行性主动脉瓣有所上升，二叶式主动脉瓣、感染性心内膜炎所致瓣膜损害变化不明显。

Firstly, the control of reentry phase and the model of RCS jets are presented. Then the flight control system is divided into two subsystems based on the time-scale separation principle. The fast states subsystem corresponds to the three body-axis angular rates, the slow states subsystem controls the angle-of-attack, sideslip angle and the rate of the bank angle about the velocity vector. Lastly, the proportional-plus-integral feedback is designed to increase the system robustness.

首先，分析了SRLV再入段的数学模型，并给出了反作用推力控制系统的控制模型；其次，将非线性动态逆方法与时标分离原则相结合，考虑飞行器姿态控制系统的外环角回路的慢变特性和内环角速度回路的快变特性，独立设计了两个回路的控制律；最后，为了增强系统的鲁棒性，分别在两个回路中引入了比例－积分反馈，有效地抑制了干扰力、力矩和非线性对消带来的逆误差。

Thus, in order to increase the percentage of our high school students who graduate from college as well as to ensure that they receive a better education in critical thinking, Omni State University should begin an intensive program to prepare our future teachers to teach high school Latin.

因此，为提高我们高中学生从大学毕业的比例并同时保证他们受到分析性思维的更好教育，Omni State University 应该开展一项集中项目来使我们未来的教师教授高中拉丁文。

Thus, in order to inc rease the percentage of our high school students who graduate from college as well as to ensure that they receive a better education in critical thinking, O mni State University should begin an intensive program to prepare our future t eachers to teach high school Latin.

因此，为提高我们高中学生从大学毕业的比例并同时保证他们受到分析性思维的更好教育，Omni State University应该开展一项集中项目来使我们未来的教师教授高中拉丁文。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。