Be-fore a problem can be solved, it must be obvious __________ the problem itself is.
Efforts to stop smoking in public areas _______ progress in Hangzhou in recent weeks.
Some economists predict that the dollar will remain weak _______ economies abroad are expected to grow faster than that of the United States.
Advertisers are increasingly cautious about taking out ads _______ children, and that is hurting children’s magazines.
Until the start of the Industrial Revolution, mankind was poor, hungry, and constantly at the _______ of disease and natural disasters.
Student loan is supposed to provide financial support for people who would _______ not be able to go to college.