风机油站的油压应控制在（）MPa。
参考答案：大于0.079
杨某14周岁，智力超常，将其某项发明与刘某达成转让协议。该转让协议（）。
A.有效
B.效力未定
C.无效
D.可撤销
His parents ______ in the country, but now they live in the city. [ ]
A. used to live
B. used to living
C. were used to live
D. are used to living
