contraction of heart的用法和樣例：
例句
- As the heart falters, the body releases adrenaline to keep the organ pumping.
例如心顫患者，體內釋放的腎腺上素能保持心臟收縮力。 - One set of wires tells the pacemaker what the heart's contraction rate is.Another set of wires tells the heart to contract if the rate is too slow or too erratic.
一組導線(xiàn)告訴心臟的收縮頻率，另一組導線(xiàn)在心率太慢或不穩定時(shí)讓心臟收縮。
