下载APP
举一反三
【单选题】混合瘤的病理学特征是
A.
肿瘤细胞含特征性嗜碱性粒
B.
由肿瘤上皮与黏液样，软骨样结构构成
C.
细胞形态学上的一致性与组织结构的多样性
D.
由含嗜酸性颗粒的柱状细胞和淋巴样组织构成
E.
由黏液细胞，表皮样细胞和中间细胞构成
【单选题】A classic series of experiments to determine the effects of overpopulation on communities of rats was conducted by a psychologist, John Calhoun．In each experiment, an equal number of male and female r...
A.
when it was double the number that could live in the enclosure without stress
B.
by removing young rats
C.
so that there was a constant number of adult rats in the enclosure
D.
all of the above are correct