a lot of knowledge可數嗎

例句：

A measure of technical knowledge is desirable in this job.

做這項工作最好多懂一些技術知識。

He has a wide knowledge of painting and music.

他在繪畫和音樂方面知識淵博。

There is a lack of knowledge about the tax system.

大家對税制缺乏瞭解。

For years we had little knowledge of what life was like inside China.

以往很多年我們對於中國國內的生活情況所知甚少。

He never made a will, to the best of my knowledge.

據我所知，他從未立過遺囑。