目前生活垃圾处理方式有哪些?
参考答案:生活垃圾无害化处理的方法种类不少,一般有垃圾卫生填埋法,垃圾堆肥法,垃圾焚化法,生物发酵法,最好都建立在垃圾分类的基础上。
He was surprised to see his mother _______ at the back of the classroom.[ ]
A. seat
B. seating
C. seated
D. to sit
下列哪种食品含有维生素A?( )
A.胡萝卜
B.木瓜
C.动物肝脏
D.苹果