题目

The president’s speech was           boring; it is ,in fact ,rather inspiring and interesting.        A．anything but   B．nothing but      C．no more       D．all but 答案：A在下列物质中有游离态氮元素存在的是 [　　] A．液氨 B．氨合成塔中平衡混合气 C．空气 D．铵态氮肥