heart可数吗

　　Her heart raced uncontrollably.

　　她的心脏难以控制地急速跳动起来。

　　My heart was knocking wildly.

　　我的心怦怦直跳。

　　His heart was beating wildly.

　　他的心脏剧烈地跳着。

　　She suffered from a weak heart.

　　她心脏不好。

　　I felt my heart beating faster.

　　我感觉心脏跳得更快了。