30分米和3米同样长。[ ]
正确
Such things are not common for me, _________ they are unusual.
A.instead
B.but
C.so
D.as a result
顿咳的好发年龄是()
A.3岁以下
B.5岁以下
C.5~7岁
D.7~10岁
E.10岁以上