difficulty的形容词是？

　　例句：

　　Do you have difficulty getting up?

　　你起床有困难吗？

　　They discussed the difficulty of studying abroad.

　　他们讨论了到国外学习的`困难。

　　Teenagers often have difficulty expressing themselves.

　　十来岁的孩子在表达思想方面常常有困难。