The world’s elderly population will exceed(超过) ____ of children by 2060,when each group ____ to account for about one fifth of the population.
The firm is now in the _____ of moving the main equipment to new place.
Without proper lessons, you could _____ a lot of bad habits when playing the piano.
It suddenly _____ to me that we could ask our neighbors to help us.
The father as well as his three children _____ skating on the freezing river every Sunday afternoon in winter.
He kept looking at her, wondering whether he _____ her somewhere.