Unit 3第六题答案
76、built with stones and bricks in ancient times; the northern border of the country could be protected
77、Although there's still a long way to walk
78、imagine how surprising; unless you see it with your own eyes
79、fun to ride/cycle around Nanjing
80、you want to go on holiday in Asia
Unit 3第七题答案
81、visit
82、June
83、Seldom
84、Far
85、Schooling
86、life
87、left-behind
88、parents
89、worried
90、develops
Unit 3第八题答案
91、huge
92、capital
93、size
94、metres
95、if
96、top
97、probably
98、quarter
99、named
100、ago
Unit 3第九题答案
略