I had never heard an English word ________ before I went to junior high school 　[ ]

I won’t allow him to make the trip alone, even if he_____ do it.

This approach, ______ more expensive than the basic one, provides us with considerably more usage flexibility

The roof fell before he had time to ________ the room to save his baby. [ ]

To the surprise of many people, in ten years the city’s population _______ by 12%.