The man often feels lonely.He seems to have______ most of his friends.
Have you considered how weak humans area volcano, hurricane or earthquake?
Can you explain ________ the sun goes down in the west?
—Someone has tidied the sitting room! —Jim __ it this morning; he couldn't bear the mess any more.
Peterson used to work in a remote mountain village school, which is only on foot.
I would appreciate ______ very much if you help me with my English.