在平面机构中，若引入一个高副，将引入一个约束，而引入一个低副将引入两个约束。运动副约束数与相对自由度数的关系是（）.
参考答案：运动副约束等于机构相对自由度数
— Were there any dolphins in the aquarium?
— ___________. We didn't see any in it.
[ ]
A. Yes, there were
B. No, there weren't
C. Yes, there are
D. No, there aren't
44岁经产妇，因葡萄胎行全子宫切除术。病理检查未见子宫肌层有增生的滋养细胞。下列哪项处理恰当？（）
A.免疫治疗
B.广谱抗生素治疗
C.随访观察
D.化疗
E.放射治疗
