莴苣lettuce可数吗

　　例句：

　　His lettuces have gone to seed.

　　他种的莴苣已结籽。

　　Thee lettuces are growing.

　　莴苣在生长。

　　My lettuces have bolted.

　　我种的莴苣已经结子了。

　　The lettuces certainly were very fine.

　　那些莴苣菜无疑是非常好。