heart可数吗?

Heart-shaped cookie cutters come in many sizes.

有多种不同大小的`心形饼干模具。

Her years of drunken bickering hardened my heart.

她常年醉酒吵闹让我的心麻木了。

Her heart was thumping as she ascended the stairs.

她上楼梯时，心怦怦跳个不停。