_______ difficult and challenging the task may be, we must finish it on time, because there is a possibility _______our work will go down in history.
When I visited her,she was in writing a lecture speech on Chinese history.
Many people take pills to make sure they will achieve or maintain their desired weight___it will lower their life expectancy(寿命).
The media actually can play a positive role in___consumer issues in some new areas, such as e-commerce and online finance services, which aren't fully covered by current laws.
It is so noisy in the restaurant and hard for us to ________ a conversation.
A harmonious society is very important, so all the laws must be strictly______.