【单选题】把燕麦胚芽鞘尖端放在琼脂小块上,正中插入生长素不能通过的云母片,琼脂被分成相等的两部分如下图。单侧光照射后,琼脂块内的生长素含量将是
【单选题】分页显示当前文件目录的DOS命令是( )
【单选题】对燕麦胚芽鞘尖端进行如下图所示的处理:①将尖端套上不透光的锡箔小帽;②将尖端下部用锡箔遮住;③在尖端纵向插入云母片;④在尖端横向插入琼脂片;⑤切去胚芽鞘尖端。下列选项中正确的是 [ ]
A.
单侧光照,①②实验结果说明感受光刺激的部位在胚芽鞘尖端
C.
把④放在匀速转盘上,给予右侧光照,将向右弯曲生长
D.
如果把放过胚芽鞘尖端的琼脂块放在⑤的一侧,则其向同侧弯曲生长
【单选题】Without proper planning, tourism can cause problems. For ex ample, too many tourists can crowd public places that are also enjoyed by the inhabitants of a country. If tourists create too much traffic,...
A.
It is extremely important to develop tourism.
B.
Building roads and hotels is essential.
C.
Support facilities are highly necessary.
D.
Planning is of great importance to tourism.
【简答题】请参看章节材料4.2中《ZEMAX实例教程》中“课程2:双透镜”,重复该内容, 给出结果,包含结构数据截图,2D结构图、像差特性图、光程差曲线图、点列图、焦点色位移曲线 和 场曲畸变曲线,每幅图适当给出简单的说明。 另外请在结果前写一段话说明,包含结构类型,焦距,方法等
【简答题】Without proper planning, tourism can cause problems. For example, too many tourists can crowd public places that are also enjoyed by the inhabitants of a country. If tourists create too much traffic, ...