As is known to all, one of the many benefits of ________ adventure travel is teaching children how to cope with ________ unexpected.

A．the; /

B．/; an

C．the; the

D．/; the

已知（x^lgx+1+1）ⁿ展开式中，末三项的二项式系数和等于22，二项式系数最大项为20000，求x的值．