诊断儿童苯丙酮尿症最常用的筛选方法是
A.血清苯丙氨酸浓度测定B.Guthrie试验C.尿三氯化铁试验D.氨基酸层析法E.苯丙氨酸耐量试验
参考答案:C
Our car _________ on the highway and we had a hard time trying to find someone who could get it ________.
A.broke up; working
B.broke down; to start
C.broke up; worked
D.broke down; starting
甘蔗田的化学除草不能用()进行。
A、西马津
B、禾大壮
C、阿特拉津
D、茅草枯