用玻璃棒搅拌出的较纯净的DNA的颜色以及DNA遇二苯胺(沸水浴)显现的颜色分别是[ ]
A.黄色、紫色
B.白色、砖红色
C.白色、蓝色
D.蓝色、砖红色
答案:C
– Where is your father now?
– He _____Hongkong. He____there for three days.
A.has gone to , has been to
B.has been to , has been
C.has gone to , has been
D.went , was
梅雨季节,银耳常贮于()
A.1~5℃
B.2~5℃
C.2~10℃
D.5~10℃
E.10~15℃