Mr.Jones became headmaster last year.是什么意思？

Mr.Jones became headmaster last year.

琼斯先生去年当了校长。

Mr

abbr. Mister 先生，Master 少爷，Mother 母亲，molecular radius 分子半径；

例句
According to police accounts, Mr and Mrs Hunt were found dead on the floor of their kitchen.
据警方称，亨特夫妇被发现死在家里厨房的地板上。

Jones

n. <美><俚>瘾，毒瘾，固着型依恋；

例句
His mother offered her apologies to the Jones family...
他的母亲向琼斯一家赔了不是。

became

v. 变为，成为（ become的过去式 ）；

例句
It became very clear that the incident was not just an aberration, it was not just a single incident.
事实已经很清楚，这件事不是偶发的，它并不是一起孤立的事件。

headmaster

n. （私立学校的）校长；

例句
I asked my headmaster if he could arrange a collection for a refugee charity.
我问校长他是否能为救济难民的慈善机构组织一次募捐。

last

n. 末尾，最后，上个，鞋楦（做鞋的模型）；vt. 经受住，到…之后，够用，足够维持（尤指某段时间）；adj. 最近的，最后的，最不可能的，惟一剩下的；vi. 持续；adv. 上一次，最近一次，最后；

例句
The last French king was Louis Philippe, who abdicated in 1848.
法国末代国王是1848年逊位的路易·菲力普。

year

n. 年，年纪，一年的期间，某年级的学生；

例句
The following year Parliament voted to abolish the death penalty for murder...
议会于翌年表决对谋杀罪废除死刑。