The United States _______one of the lowest smoking rates -25.5 percent of the population.
Miss Wang is ________ a teacher. She’s our best friend.
He had no money, _________ anyone whom he could borrow from.
--- Do you suppose it is going to rain over the weekend? --- _______.
To learn English well, listening is also of great importance ______ reading and writing.
After arriving in the United States, this 20-year-old Chinese student found it rather difficult to _______ living on his own.