单项选择题
We usually keep a large supply （）stock.
A.at B.on C.in
单项选择题 Inordertomakeproperreservations，willyousendyouracceptancetotheattentionofProfessorChen（）aweekbeforethatday？
单项选择题 Iplantousethemediamixto（）reachour.
单项选择题 SoIhaveanumberofotherupmysleeve，aswell（）.
