α-Al2O3晶体中Al离子填充在()八面体空隙中。
A.1/2
B.1/3
C.2/3
D.3/4
参考答案:C
At the foot of the mountain ______.
A.a village lie
B.lies a village
C.does a village lie
D.lying a village
既阻断β受体又阻断α受体的是()
A.普萘洛尔
B.拉贝洛尔
C.阿托品
D.酚妥拉明
E.美托洛尔