单项选择题
On my left（）a wide river; on my right, a dark forest.
A.has been B.was C.are D.would be
单项选择题 On formal（）, people pay more attention to manners.
单项选择题 On average, a successful lawyer has to talk to several（）a day.
单项选择题 On（）side of the street there are some trees.
