There is widespread concern that the rising unemployment may _____ a threat to social stability.

Those people are speaking a language I can＇t understand. They must be ____.

You can＇t expect me to remember such ____ details.

Many a teacher ____ it difficult to teach English grammar.

A horse and carriage ____ not much in use today.

Food and meal services also ____ local culture.

____ today, he would get to Beijing by Wednesday.

Some technicians have little or no direct ____ the public.

Many airlines offer one-service flights, especially on short, ____ traveled routes.

There are several ways in which airline service can be ____ categories.

Every airline＇s flight has a number to ____ it.