“珍妮纺纱开先河，蒸汽推动世界波”所反映的是（    ）

The young lady prefers dressing up for a party to_______ by others.

作物脱毒、改善畜产品的品质、抗除草剂作物、可保存的干扰素、检测有毒物质依次是下列哪项生物技术的应用   
①基因工程   ②细胞工程   ③蛋白质工程   

Playing QQ’s “Happy Farm” by planting, watering, fertilizing, spraying, harvesting and selling of virtual vegetables, fruits and flowers, we can find out _____ all the excitement is about．

如图,在菱形ABCD中,E,F分别是AB,AC的中点,如果EF=2,那么菱形的周长为____．