The exercises are designed to strengthen your stomach muscles. 
这些活动目的`在于增强你的腹部肌肉。 Muscles contract and relax during physical activity. 身体活动时肌肉收缩放松。 He didn't move a muscle. 他一动不动地站着。 The heart muscles contract to expel the blood. 心脏肌肉收缩以挤压出血液。 The exercise consists of stretching and contracting the leg muscles. 此项训练包括伸展和收缩腿部肌肉。 上一篇:patient的名词形式 下一篇:理解的英文短语用make |