If you want to change the world, you _________ change yourself first.
A：needs
B：have to
C：need
D：had to
我国省级行政区的设立源于（ ）
实验1：阔叶（雌）×窄叶（雄）→子代雌株全为阔叶，雄株全为阔叶
实验2：窄叶（雌）×阔叶（雄）→子代雌株全为阔叶，雄株全为窄叶
