(2013·山东烟台市二模)Mr. Johnson, ________ as a manager for many years, found it hard to be an ordinary clerk again.

______ in the school campus in spring, we will always noitce a colorful display of flowers.

.At this moment the bell rang _______ the end of class.　

We don’t allow ___in the office. But you are allowed ____in the rest room. 

______ their service, the workers of the hotel are active in learning English.