题目

The twins were separated at birth and brought up in entirely different families. A . when they grew up B . on birthdays C . when they were born 答案：C将燕麦胚芽鞘做如图所示的处理，一段时间后，甲、乙两琼脂块上的生长素浓度（   ） A、甲>乙   B、甲<乙   C、甲=乙   D、无法比较