【单选题】DNA复制之初,参与从超螺旋结构解开双股链的酶或因子是
【简答题】根据括号内的汉语提示,用句末括号内的英语单词完成句子 Such knowledge is still useful ______ (当应用) to similar situations inother countries. ( when )
【简答题】根据括号内的汉语提示,用句末括号内的英语单词完成句子 If times ______ (变了) , have our ways of thinking changed too? ( change )