李艳同学在做“探究凸透镜成像原理”实验时，当蜡烛距凸透镜30cm时，在距透镜15cm的光屛上找到清晰的倒立、缩小的像．当蜡烛距透镜15cm时，移动光屛，则光屛上（　　）

下列与动物细胞培养有关的表述中，不正确的是(　　)

阅读下列短文,从每小题所给的A、B、C、D四个选项中选出一个最佳选项。

EASTGATES  YANGZHOU

Rollerworld is a public skating rink（旱冰场）that welcomes everyone from beginners to experts.

NOTICE

— under 12's must be taken care of by an adult.

— small cost for adults watching children

— no dirty or dangerous skates

— dress must be neat

— no jackets, hats or open clothing to be worn

— no newspapers, books, magazines, games allowed in Roller Café or Roller Bar

— no smoking except in Roller Bar and smoking room of Roller Café

— over 18's only in Roller Bar

“Roller skating fun for everyone”