-May I trouble you with the question?-Sorry, but it is______my knowledge.
-- I think he is selfish. -- _______, he is very noble and generous.
We went to the Lincoln Memorial yesterday, ___, not surprisingly, was crowded with visitors from all over the world.
Our monitor requested that ________.
In fact___ is a hard job for the police to keep order in an important football match.
The reason _____ he was driving his car so fast was _____ he would be late.