下列关于砹(85At)及其化合物的说法中,正确的是( )
A.稳定性:HAt>HCl
B.氧化性:At2>I2
C.At2为分子晶体
D.NaAt的水溶液呈碱性
答案:C
数字化音频的质量取决于采样频率和量化位数,B位二进制数字可以表示()个不同的量化电平。
A.
B.
C.
D.
What does Paul look like? [ ]
A. He's tall and has brown hair.
B. He's clever.
C. He's my brother.
D. He's a worker.