The professor found himself constantly （）the question: "How could anyone do these things"

More than 85 percent of French Canada's population spea...

单项选择题More than 85 percent of French Canada's population speaks French as a mother tongue and （）to the Roman Catholic faith.

As visiting scholars, they willingly （）to the customs o...

单项选择题As visiting scholars, they willingly （）to the customs of the country they live in.

We find that some birds （）twice a year between hot and ...

单项选择题We find that some birds （）twice a year between hot and cold countries.