He devoted himself to writing out a long-term policy __________ the country.
The fact that she was foreign made __________ difficult for her to get a job in that country.
I had great difficulty __________ the suitable food on the menu in that restaurant.
—What made you so tired?—__________ driving all day.
Rather than __________ on a crowded bus, he always prefers __________ a bike.
Jiaxing is such a beautiful city that it is well worth __________.