He was so deep in thought, thinking of the problem _________he knocked into the tree without noticing it.
A piece of ______ music will make you happy.
Greatly ______, the students made up their minds to work at English even harder.
——Thank you for your help. ——________.
______ with extraordinary strength, the sportsman raised the huge box onto his shoulders.
——Do you mind my taking this seat? ——________.