问题
选择题
A low-carbon lifestyle is of great benefit to improve_____ world environment. Nothing can be enjoyed from it until you have____ deep understanding of it, though.
A．a; the
B．/; a
C．the; /
D．the; a
答案
答案：D
考查冠词.结合语境可知上文特指世界的环境,故用定冠词.下文泛指任何中深入的理解,故用不定冠词,选D.