Working as a manager, Rebecca found it hard ______ between work and her family.
____ with the size of the whole earth, the highest mountain doesn’t seem high at all.
I ______ my university professor in the supermarket near my house, which was out of my expectation.
I was not _______her presence till she spoke to me.
There is no need ______ because Mr. Smith is still sleeping.
When ____about his family, he is always refusing to answer.