State legislators (or people who make laws in the government at the state level) used to elect (or choose) senators.
参议员曾经由州议员（州政府中的立法者）选出。
However, since 1913, senators have been elected directly by the votes of the citizens who live in their state.
然而，1913年以后，参议员就一直是由他们州的选民直接选出。
Once a senator is elected, he or she can serve for the full six years before having to run for election (or try to get the public position through votes) again.
参议员一旦当选，在寻求连任（通过选举得到政府部门中的职位）之前，他或她任满六年。
Sometimes, however, senators are expelled (or forced to leave) before their term ends.
然而，有时参议员在任期结束之前就被驱逐（被强制离开）了。
This has happened only 15 times so far and the last time was in 1862.
到目前为止，这种情况只发生了15次，最后一次出现在1862年。
Since then, the Senate has tried to expel some senators, but those senators have resigned (or chosen to leave that job) before the other senators could make them leave.
从那以后，参议院也驱逐过一些参议员，但在其他参议员要把那些参议员赶走之前，他们就已经辞职（选择离开那个岗位）了。
When a vacancy (or an open position) is available, maybe because a senator has resigned or died, there is usually a special election to find a new senator to represent that state.
因为参议员辞职或死亡而出现岗位空缺的时候，就会有专门选举选出新参议员来代表那个州。
Senators who are elected this way finish the time left in the previous senator's six-year term and usually do not serve the full six years.
以这种方式当选的参议员其任期为至原任者的六年任期届满为止，而非任满六年的任期。
译文为秀哈英语翻译，未经授权请勿转载！
