这个需要一点背景资料，你单纯给出一句话不好翻译。

(a)    In life insurance policyholders, the most likely
people to lapse their policies are those in good
health.This affects the resulting mortality of the
insured population.

(b) Terms assurances may have the option to
renew at the end of the term at normal rates
without any evidence of good health:
• healthy lives may exercise the option but
they can also go elsewhere
• unhealthy lives may not be able to go
elsewhere making this option very
attractive to them


(c) Consider the mortality of active members (not
retired) of a pension scheme. This population:
• increases by new people employed (mainly
healthy people)
• decreases by the people who retire early
(mainly ill people retire early)
The selective nature of these ‘entrants’ and
‘leavers’ affects the mortality of the active
members.


这个就是notes 里面的例子  可以帮下忙么？