Tom ws ill yesterdy, ________ he didn’t go to school. But he’s better now.orB．butC．forD．soTom ws ill yesterdy, ________ he didn’t go to school. But he’s better now.or B．but C．for D．so

Json ws ill yesterdy, ________ he didn’t go to school.o...

单项选择题Json ws ill yesterdy, ________ he didn’t go to school.orB．butC．forD．soJson ws ill yesterdy, ________ he didn’t go to school.or B．but C．for D．so

It ws _______ he ws ill tht he didn’t go to school.sinc...

多项选择题It ws _______ he ws ill tht he didn’t go to school.sinceB．s C．becuseD．thoughIt ws _______ he ws ill tht he didn’t go to school.since B．s C．becuse D．though

下列关于遗传病的叙述，正确的是（） ①先天性疾病都是遗传病 ②多基因遗传病在群体中的发病率比单基因遗传病高 ③...

单项选择题下列关于遗传病的叙述，正确的是（） ①先天性疾病都是遗传病 ②多基因遗传病在群体中的发病率比单基因遗传病高 ③21三体综合征属于性染色体病 ④软骨发育不全是细胞中一个基因缺陷就可患病 ⑤抗维生素D佝偻病的遗传方式属于伴性遗传⑥基因突变是单基因遗传病的根本原因