(单选题)10: 设X与Y为任意两个随机变量，它们的相关系数ρ= 0 ，则X与Y（　）成立。 A: 不相关 B: 正相关 C: 负相关 D: 独立 ...

(单选题)4: 利用含有待估参数及（ )其它未知参数的估计量，对于给定的样本值进行计算，求出的估计量的值称为该参数的点估计值 A: 不含有 B: 含有 C: 可能 D: 以上都不对 ...

(单选题)21: I remember ___ to help us if we ever get into trouble. A: once offering B: him once offering C: him to offer D: to offer him ...

(单选题)16: That can't be happenning to me.(选择最恰当的译文) A: 这不可能落到我头上啊 B: 这不会落到我头上。 ...

(单选题)10: Let us ___ to the next item on the agenda. A: continue B: proceed C: keep D: stop ...

(单选题)12: She can stay in her workroom for 10 hours without eating or sleeping, all her attention ___ her A: focusing on B: focused on C: focusing in D: focused in ...

(单选题)6: when he realized the police had spotted him, the man ___ the exit as quickly as possible. A: made for B: made off C: made up D: made out ...

(单选题)8: Many people complain of the rapid ___ of modern life. A: rate B: pace C: speed D: growth ...

(单选题)2: Anna was reading a piece of science fiction, completely ___ to the outside world. A: having been lost B: to be lost C: losing D: lost ...

(单选题)10: “I didn’t know what to say” means ___. A: I was puzzled about it B: I suspected it C: I was at a loss for words D: I would rather do it ...