It is difficult to ________ a conversation with someone who only says “Yes” and “No”.

Every time he had a chance , he would talk about the great difficulty he had       in the new country .

We_____ the old scientist________ his contribution________ the country.

We should ________ ourselves assiduously and faithfully to the duties of our profession.

Students often ______ a lot of difficulties when they communicate with foreigners for the first time.