一串小彩灯，规格都是“4V 0.2A”，每个小彩灯的结构如图所示，在正常情况下，细金属丝由于表面有一层氧化铜而与灯丝支架不导通，若加上200V以上电压时，氧化铜被击穿，细金属丝与灯丝支架导通．若将这种规格的小彩灯接入220V电路中，为使小彩灯不被烧坏，至少应将____ 个彩灯串联；若其中一只小彩灯的灯丝被烧断，其它小彩灯还能不能发光？为什么？____ ，因为____ 

    Mr Brown lives in a nice house in a small town with his wife(妻子), Mrs Brown. From Monday to Friday he works in an office near his house. He is free on Saturdays and Sundays. He has a nice garden beside his house. He likes growing flowers and he often works in the garden on Saturdays and Sundays. The flowers are very beautiful and Mrs Brown likes them very much. She often helps Mr Brown.