John usually goes to school by bus. He leaves (离开)his house at seven and gets to school at about seven twenty. His school is on the hill.

    From Monday to Friday John usually has four classes every day. He likes English. He wants to be an English teacher. He hopes he will go to the USA to study English one day. On Sundays, he often goes to the library with his friends, but sometimes they go to see movies.

阅读下列材料，回答问题。

材料1：“苏湖熟，天下足。”

材料2：“爆竹声中一岁除，春风送暖入屠苏。千门万户瞳瞳日，总把新桃换旧符。”

材料3：关于《资治通鉴》一书，司马光在《进通鉴表》中曾说：“专取国家盛衰，系民生休戚，善可为法，恶可为戒者。”

材料4：上海世博会中国馆多媒体动漫长卷《清明上河图》，用北宋繁荣的都市风貌，辉映着“城市让生活更美好”的主题，极大地吸引了参观者的兴趣。

问题：

____

已知某两种物质在一定条件下发生化学反应，其微观示意图如下，下列说法正确的是

①限制性核酸内切酶②DNA水解酶③DNA聚合酶④DNA连接酶⑤RNA聚合酶⑥解旋酶．