A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just a bunch of individual components (零件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. “The added difficulty with such a project is that actually none of those components are off the shelf and so we have to make them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of individual components, each of which individually has to perform well, and then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    Wood says the design offers a new way to study flight mechanics and control at insect- scale. Yet, the power, sensing and computation technologies on board could have much broader applications (应用). “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

It's ______me.（  ）

某养鸡场的鸡一听到主人的哨声就会集结来“吃饭”；这是其主人常用鸡、哨子和米作为训练材料进行不断地训练的结果。则在训练过程中：

将喂米与哨声结合时，是先给予哨声，还是先给予食物？____；

将用于实验的鸡分为实验组和对照组，给予哨声刺激的是____组。