有11瓶饮料，其中一瓶变质了（略重一些），用天平称，至少称______次一定能找出这瓶次品．
第一次：从11瓶饮料中，任取10瓶，平均分成2份，每份5瓶，分别放在天平秤两端，若天平秤平衡，则未取那瓶即为变质的饮料，若天平秤不平衡；
第二次：从天平秤较低端的5瓶饮料中，任取4瓶，平均分成2份，每份2瓶，分别放在天平秤两端，若天平秤平衡，则未取那瓶即为变质的饮料，若天平秤不平衡；
第三次：把天平秤较低端的2瓶饮料，分别放在天平秤两端，天平秤较低端的饮料即为次品，
故答案为：3．
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| This is a photo of a family. Five __1 are in the photo. They are all in a __2_ .The boy is Barry Hand. _3 is a student. His school is in ShenZhen. His parents are running stars. They can _4 very fast(快). Barry __5 two sisters. One is Mary _6 the other is Mona. They are also students. Barry __7 math. It is difficult. He likes sports. He __8_ basketball every day. His sisters like __9 . It is a great language(语言). The hand family has a telephone. Its _10 is 773-1068.
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