既能分泌雄激素又能分泌雌激素的卵巢肿瘤是（）
A.颗粒细胞瘤
B.卵泡膜细胞瘤
C.睾丸母细胞瘤
D.未成熟畸胎瘤
E.黏液性囊腺瘤
参考答案：C
蛔虫性肠梗阻的诱因主要是()。
A．营养不良
B．习惯性便秘
C．驱虫不当与发热
D．溃疡性结肠炎
E．肠管先天性畸形
Which of the following statements is false().
A. People know exactly how and why humans domesticated the first dogs.
B. People learned to selectively breed dogs for certain specific tasks.
C. Of all the domesticated animals, dogs seem closest to their owners.
D. Wolves raised in captivity still fall to understand human gestures:
