单项选择题
A.business B.accident C.matter D.event
One cannot learn a foreign language well（）he studies ha...
单项选择题One cannot learn a foreign language well（）he studies hard.
A.unless B.if C.as D.when
One and a half hour（）since we arrive. No one has come t...
单项选择题One and a half hour（）since we arrive. No one has come to meet us.
A.have passed B.was passed C.pass D.has passed
On my left（）a wide river; on my right, a dark forest.A....
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
