已知{a_n}为等差数列，其公差为－2，且a₇是a₃与a₉的等比中项，S_n为{a_n}的前n项和，

n∈N*，则S₁₀的值为[ ]

A．－110      

B．－90          

C．90      

D．110

A lot of small companies have to fight for _____ in such economic climate.   [ ]

A. survival                  

B. survivor  

C. survive                

D. exist