He said there was a great gap between the views expressed in the media and what（）people were thinking.

单项选择题Backward languages fall behind Western languages in（）

A. ways to transfer ideas
B. forms to satisfy needs
B. abilities to answer description
D. systems to expand vocabulary

单项选择题In lines 13-17, why does the author compare tree roots with growing salt crystals（）

A. They both force hard surfaces to crack.
B. They both grow as long as water is available.
C. They both reach quickly to a rise in temperature.
D. They both cause salty water to rise from the groundwater table.