原材料引用(Materials)

It said people should increase the number of chest presses from fifteen to thirty for every two breaths given.

Gordon Ewy is a heart doctor at the University of Arizona College of Medicine in Tucson.

He wrote a report that appeared with the study.

信息与事实(Facts)

ir 发音时由第一个音i向卷舌音r滑动

er 先发前元音e，同时舌尖轻触下齿，然后很快滑向r音

感受与评价(Comments)

无

累计练习小时数(Hours)

0.5h