下列哪一个分离过程不属于非均相物系的分离过程()。
A、沉降
B、结晶
C、过滤
D、离心分离
参考答案:B
Your brother promised to help me and ______the next day.
A.neither he did and neither did you
B.so he did and so did you
C.neither did he and neither you did
D.so did he and so did you
雅连为的特征()
A.圆锥形或羊角状,表面灰黄色或棕褐色
B.不规则的团块或长圆形,表面灰黑或灰棕色
C.圆柱形,略弯曲,表面灰棕色至暗棕色,有节、芽、叶柄基和根痕
D.扁圆柱形,表面灰黄色,外皮横向断裂而露出木部,形似连珠
E.根茎粗短,下生根数条,表面棕红或暗棕红色