______envident by now,the number and diversity of personality theories are indeed remarkable.
A.Since should be B.As would be.C Since will be D As should be
答：最佳选项应该是D.
首先大家对as 引导非限制性定语从句,as指后面的整句,在从句中作主语,有“正如”之意,应该不陌生：
As is known to all,the earth goes around the sun.
所以答案就在BD之中.
should有“应该”之意,也就是说（by now) 到现在后面所说的事,“应该”很明显了.
现在应该很明显了,个性理论的数量和多样性都的确值得人们注意.