A:研究猫叫综合征的遗传方式,在学校内随机抽样调查
B:研究红绿色盲症的遗传方式,在患者家系中调查
C:研究青少年型糖尿病,在患者家系中进行调查
D:研究艾滋病的遗传方式,在市中心随机抽样调查
有____个
□有____个
○有____个
△有____个
It's six o'clock in the afternoon. It's time for 1!Jenny and Li Ming are2. Jenny's mother is 3 in the kitchen. Jenny and Li Ming help Mrs. Smith 4 the vegetables. After dinner, Mrs. Smith washes the 5 dishes. Li Ming dries the dishes.
解方程或化简