她觉得难以完成给自己定下的任务。

She felt unequal to the task she had set herself.

《牛津词典》

由于AIX内存优化，这常常是个难以完成的任务。

This is often a hard task, due to AIX optimization of memory.

youdao

但我必须从长远目标来看法网，毕竟这个大奖赛对我来说非常难以完成。

But just try to think a little bit more long-term, knowing that this was a very difficult Slam for me to compete in anyway.

youdao