How（）the cargo at loading port?
A.about
B.in
C.with
D.from
参考答案：A
This kind of fruit ___________ large amounts of vitamin, vitamin C.
A. includes; including B. takes; containing
C. holds; included D. contains; including
A，B两种元素可形成AB型离子化合物，A，B两种离子的核外电子数之和为20，则两种元素所处的周期为[ ]
A．在同一周期
B．一种在第一周期，一种在第二周期
C．一种在第二周期，一种在第三周期
D．一种在第三周期，一种在第四周期
