. From this simple concept ________ that has caused a great change in farming.

A．has developed a technique

B．has a technique developed

C．a technique has developed

D．developed as a technique has

礼仪是交往的产物，语法是说话的产物，逻辑是思考的产物。人们长期形成的做事情的方式和规范，无非是人类知识和经验的总结。这表明（）

①文化实质上是一种精神力量

②文化是人们社会实践的产物

③文化素养是逐步培养出来的

④文化现象无时不在，无处不有

A.②③

B.①②

C.①③

D.①④