tenable
adj
1 that can be defended successfully against opposition or attack 可防守的; 守得住的; 可维护或防护的
a tenable position 可防守的位置
The view that the earth is flat is no longer tenable. 认为地球是平的这一观点站不住脚了.
2 [pred 作表语]
~ (for...) (of an office or postion) that can be held (for a certain time) (指职务或职位)可保有, 可维持(一定时间)
The lectureship is tenable for a period of three years. 讲师这一职位任期三年.
If there's anything else I can do , please tell me.
如果有任何事情我能效劳的话,请告诉我。
Alternatively, if the star were small, the life-supporting planet would have to have a close orbit round it and also provide the perfect conditions for life forms to develop.