胆大的（形容词，非正式）

(adjective, INFORMAL) Brave; appearing to be without fear.

EXAMPLE: We hired two gutsy young sales representatives who weren抰 afraid of talking with anyone, so they both became quite successful.

我们雇用了两位胆大的销售代表，他们俩不害怕和任何人说话，所以都非常成功。

铁石心肠（成语）

(IDIOM) Unyielding; lacking compassion; unsympathetic.

EXAMPLE: The wealthy old woman was as hard as nails, and never gave help of any kind to her friends or family members if they were experiencing difficulties.

这位有钱的老妇人是铁石心肠，在朋友或家人有困难时从不给他们任何形式的帮助。