She felt nervous, increasingly lacking in confidence about herself.
她感到紧张，对自己越来越缺乏信心。
These tasks were repetitive, lengthy and lacking any intrinsic interest.
这些作业重复冗长，没有什么意义。
What was lacking was a way of giving such images permanent form.
真正缺少的'是将这些影像永久保存下来的方法。