普通平键根据( )不同,可分为A型、B型和C型三种。
A.尺寸的大小
B.端部的形状
C.截面的形状
参考答案:B
_______ she is ill, _______ she goes to school.
A.Although; /
B.Although; but
C.But; although
D.Because; /
清除果蔬残留农药的方法有______。
A.汆水
B.熏蒸
C.机械刷洗
D.食盐水洗涤