云英岩化
参考答案:
一种重要的高温气水热液蚀变作用,主要产在花岗岩当中,蚀变后云英岩呈浅灰色、灰色,中粗粒结构。具有花岗变晶、花岗鳞片变晶,以及鳞片变晶结构。
Usually children under six are not ______ to school except those of extraordinary intelligence.[ ]
A. permitted
B. admitted
C. accepted
D. received
为什么要对种子生产实行许可制度?