With a lot of difficult problems _______, the manager felt worried all the time.

4. Mr. Smith ______ that he had made a mistake and that he had corrected it.

The walls of the rooms are said ___white inno time.

How’s your tour around the North Lake? Is it beautiful?—It __________ be, but it is now heavily polluted.

country, ________ Britain,it has been said, can one experience four seasons in the course of a singleday