下列成土母岩中含硒量相对较高的是()
A.沉积岩
B.页岩
C.花岗岩
D.云母岩
E.冰晶岩
参考答案:A
___ an answer from her husband, Emily decided to send him another email.
A.Not having received
B.Having not
C.Receiving not
D.Not receiving
设F是一个森林,B是由F转换得到的二叉树,F中有几个非叶结点,则B中右指针域为空的结点有( )个。
A.n-1
B.n
C.n+1
D.n+2