1只小狗的质量=4只鸭的质量，1只鸭的质量=5只小鸡的质量，1只小狗=（ ）只小鸡的质量。
20
China’s economic development has made ______ rapid progress in the past 10 years, and young people have made ______ great contribution to this progress.
A．a; a
B．the; /
C．/; a
D．/; /
光谷位于哪里？（）
A.北京
B.上海
C.长春
D.武汉
