困难多的

Their difficulties are increasing.

他们的困难越来越多。

The times of chirospasm became more and more, my speaking became more and more lisping and swallowing also became the biggest difficulty.

手痉挛的次数越来越多，说话变得越来越含糊，吞咽成为最大的困难。

Because the mature tissue of velvetleaf contains lots of secondary metabolites such as alkaloid and phenolic, it is difficult to obtain high purity DNA from mature tissue of velvetleaf.

摘要青麻成类、黄酮类等次生代谢物较多，要从提取出高纯度的DNA比较困难。