Dogs have a very good ______ of smell and are often used to search for survivors in the earthquake.
A:sense
B:view
C:meaning
D:idea
已知a﹣b=1,则a2﹣b2﹣2b的值为( )
学会生活自理是提高自身生存能力、竞争能力和自我发展能力的基础。( )