Most companies’ marketing effort is focused on getting customers, with little attention _______ to keeping them.
The medicine _______ bitter.
They are also worried _________ all the students are able to make good use of the spare time after school.
A wonderful sports meeting ________on our school playground last Friday and Saturday.
______ the help of an American teacher, we can learn real English.
There are various performances ______dancing and singing in the party.