Liu Mei often helps her mother _____ hou 发布时间:2017-05-02 16:44 │ 来源:www.tikuol.com 题型:选择题 问题: Liu Mei often helps her mother _____ housework. [ ]A. does B. do C. doing D. to doing
题型:选择题 关于心肌最大缩短速度(Vmax)的描述正确的是()。A.是指在适当的后负荷下,心肌收缩时缩短速度最大B.它受前后负荷的影响C.可直接测量D.它能反映心肌舒张功能E.Vmax增大,心肌收缩力增强 查看答案