如图是细菌结构模式图，请据图回答：
Our teachers have been with us for nearly three years _______ we came to junior high school. We should thank them for what they have done for us.
下面是张华为妈妈设计的几份午餐食谱，你认为最合理的是（ ）
规范、正确的实验操作对实验结果、人身安全都非常重要．下列实验操作中正确的是（ ）
为转移