下列说法不正确的是[ ]
A．O2与O3互为同素异形体
B．丁烷与异丁烷是同分异构体
C．SmSm是同一种核素
D．H、D、T互为同位素
答案：C
弥漫性血管内凝血早期可选用（）。
A．叶酸
B．维生素K
C．尿激酶
D．氨甲苯酸
E．肝素
An analyst has recently determined that only 60 percent of all U. S. pension funds have holdings in hedge funds. In evaluating this probability, a random sample of 50 U. S. pension funds is taken. The number of U. S. pension funds in the sample of 50 that have hedge funds in their portfolio would most accurately be described as a:（）
A. binomial random variable.
B. Bernoulli random variable.
C. continuous random variable.
Sm
Sm是同一种核素
SmSm是同一种核素