较早出现淋巴和血行转移的肺癌是（）
A.腺癌
B.鳞癌
C.大细胞癌
D.小细胞癌
E.Pancoast瘤
参考答案：D
函数f(x)=ax2+(a-3)x+1在区间[-1,+∞)上是递减的,则实数a的取值范围是( )
A．[-3,0)
B．(-∞,-3]
C．[-2,0]
D．[-3,0]
Which of the following statements about hypothesis testing is FALSE（）
A. The null hypothesis is a statement about the value of a population parameter.
B. A Type Ⅱ error is failing to reject a false null hypothesis.
C. If the alternative hypothesis is Ha: μ＞μ0, a two - tailed test is appropriate.
