He has been to America twice, _____.
On top of a gardener, Mrs. Johnsons has also taken up an _______ as a wine-maker.
Daniel is one of the students in the class who never _______ a mistake even when it is pointed out to him.
In 2014, a series of important reform measures were introduced in China, many of which are so closely associated with the interests of the general public _______ almost each person could benefit from in life.
—Mum, where are my new socks?— How _______ I know? You’d better not put your things everywhere.
It is not ________ it is useful to study nature but he takes pleasure that the scientist study nature.