题目

下图为显微镜下观察洋葱鳞片叶表皮细胞临时装片的几个视野．请据图回答问题： （1） 要使视野从①变为②，应将装片向 移动． （2） 本实验使用的物镜有10×和4×两种，要使视野从②变为③，应选用的物镜是 ． （3） 要使视野从③变为④，应调节 准焦螺旋． （4） 在制作临时装片时，盖上盖玻片的正确方法是 ． （5） 与动物细胞相比，植物细胞特有的结构是 、 和 ．Well，Mrs．Evans，I've done my best to look after David．I've tidied his room up every day，got him a meal together whenever he needed one and made sure he's always had a clean shirt to put on．It's not been easy. With two of my own to worry about，as well, David's had the best of attention，I must say．But now because I asked him to give up bringing that American friend of his home he has got quite miserable and unfriendly．He comes in at all hours and his behavior-well it’s quite hard to put up with—and it's all because of his friend．I'm sure he's a bad influence．You see，David's a visitor and doesn't fully understand our ways．     He used to study in most evenings．He's got through quite a bit of work．He did up his room quite nicely，with bookshelves and large posters．He'd ask Mr．Smith and me up for a drink and cheer us up with songs from his country．He's very good atお the guitar，you know．     I don't want to appear as if I'm running after him but it's about time we made it up，I'm sure he's upset because I told him off．It might be a good idea to take him out for a meal，perhaps even with his friend．I don't know whether it will do any good but we can try．I'm glad I've had this little chat with you，Mrs．Evans，and I'll let you know how I get on． 1. David is________． A．an American friend    B．Mrs．Smith's son C．a visiting student    D．a singer 2．Mrs．Smith believes that David is not the cause of the quarrel but that the main cause is__________. A．Mr．Smith　　　　  B．too much homework C．David's friend　　 D．David's behavior 3.Mrs．Smith wants to make up the quarrel by__________.   A．cooking a meal   B．giving them drinks   C. inviting David and his friend out   D．running after David 4. David's present attitude to Mrs．Smith is___________．   A．very attentive　　   B．unfriendly   C．cheerful　　　　　　 D．incomprehensible