heart可數嗎?

　　Heart-shaped cookie cutters come in many sizes.

　　有多種不同大小的心形餅干模具。

　　Her years of drunken bickering hardened my heart.

　　她常年醉酒吵鬧讓我的心麻木了。

　　Her heart was thumping as she ascended the stairs.

　　她上樓梯時，心怦怦跳個不停。