题目

制作洋葱鳞片叶内表皮细胞临时装片时，首先要在洁净的载坡片中央滴一滴 （     ） A．清水        B．生理盐水      C．碘液           D．酒精        答案：AThere are usually _________ people in the supermarket every weekend. [     ]A. too much B. much tooC. many too     D. too many