有读者问一道选择题：
(1)There are a lot of problems_________us at the moment.
A. faced B. facing C. to face D. to be faced
为什么应选B? 它和C有何区别？
这里的facing是现在分词，其意为“面对着”，这种用法常可见到，再如：
(2)I live in a house facing the river.
(3)In learning English pronunciation is one of worst difficulties facing us.
这里不可用to face（表未来），因为有时间状语at the moment。
