阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。 In much of Asia,especially the so-called“ricebowl” cultures of China,Japan,Korea,41 Vietnam,food is usually eaten with chopsticks. Chopsticks are usually two long,thin piecesof wood or bamboo.They can also be made of plastic,animal bone ormetal.Sometimes chopsticks are quite artistic.Truly elegant chopsticks might42 (make)of gold and silver with Chinesecharacters.Skilled workers also combine various hardwoods and metal 43 (create)special designs. The Chinese haveused chopsticks for five thousand years.People probably cooked their rood inlarge pots, 44 (use)twigs(树枝)to remove it.Over time,45 thepopulation grew,people began cuttingfood into small pieces so it would cook more quickly. Food in small pieces could be eaten easilywith twigs which46 (gradual)turnedinto chopsticks. Some people thinkthat the great Chinese scholar Confucius, 46 (gradual)turned into chopsticks. Some people think that the great Chinesescholar Confucius,47 lived fromroughly 551 to 479 B.C.,influenced the48 (develop)of chopsticks.Confucius believed knives would remind peopleof killings and 49 (be)tooviolent for use at the table. Chopsticks are not used everywhere inAsia.In India,for example,most people traditionally eat 50 their hands.