His speedy promotion is from sheer ability.是什么意思？

His speedy promotion is from sheer ability.

他全凭才干而被迅速提拔。

his

pron. (he的所有格)他的，(he的物主代词)他的东西；det. 属于他的，用于名词前，自己的，指某人的，上帝的；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

speedy

adj. 快的，迅速的，敏捷的；

例句
She leaps in one bound onto her pony's back for a speedy canter around the ring...
她纵身一跃骑上了马背，绕着场地策马慢跑。

promotion

n. 促进，增进，提升，升级，（商品等的）推广，发扬；

例句
His job is the discovery and promotion of new artists.
他的任务就是发现并推出艺术新人。

is

vt.& vi. 是（be的三单形式；n. 存在；

例句
Bollinger 'RD' is a rare, highly prized wine.
博林格RD香槟是一种名贵的备受推崇的葡萄酒。

from

prep. （表示时间）从…，（表示原因）因为，（表示来源）来自…，（表示分离）与…分离[隔开]；

例句
...an abortive attempt to prevent the current President from taking office.
企图阻止现任总统连任的失败尝试

sheer

v. （使）偏航，（使）转向；adv. 完全地，全然，垂直地，陡峭地；n. 舷弧，单锚系泊的船位，偏离的方向，船体型线；adj. 完全的，全然的，极薄的，几乎垂直地，陡峭的，绝对的；

例句
For sheer scale and grandeur, Leeds Castle in Kent takes some beating.
单从规模和气势来说，肯特的利兹城堡独领风骚。

ability

n. 能力，资格，能耐，才能；

例句
The public never had faith in his ability to handle the job...
公众从来不相信他有能力胜任这一职位。