翻译：直到上世纪初，人们才了解点对于我们为生活有着重要影响。（not……until）

从知道上世纪处这个时间状语可知,从句用一般过去时,主句应该用过去完成时.当until+表示时间段的的名词是，主句常用完成时。

People had not known the inportance effect of point on our life until the biginning of last century.

People do not know the importance of 点 until the
begining of last 世纪。
PS两个词自己查，我不确定，其它应该是对的。

People did not realise the important effect of dot on man's life until the begining of last century.

People did not know the importance effect of the life until the last century.