根据中文及首字母填写单词。

      Come and meet my family! Look! This is my m___________ (妈妈). She's a n___________ (护士).

This is my f___________ (爸爸). He's a d___________ (司机). This is my aunt. She's a t___________

(教师). This is my uncle. He's a d___________ (医生). My grandpa and grandma are f__________s (农民).

由二氧化碳引发的温室效应受到人们越来越多的关注，下列哪种因素不是导致大气中二氧化碳含量升高的主要原因（）.

A.人类的呼吸

B.火山爆发

C.汽车尾气排放

D.燃料燃烧