At last we came to a mountain, at the top of which ______,
Our son doesn’t know what to ______ at the university;he can’t make up his mind about his future.
I’m living in the apartment nearby. Come and see me whenever________.
—I hear that you will be on travel again. —Yeah. My boss __________ for me to discuss business details with someone from another company.
Not until the early years of the 19th century ________ what heat was.
__________cleaning the yard and making up the beds for the old,we also read newspapers for them and had chats with them.