He sat behind a desk laboriously writing with an Army issue pen.是什么意思？

He sat behind a desk laboriously writing with an Army issue pen.

他坐在书桌后吃力地写着，用的是一支部队发的钢笔。

he

pron. 他，它，一个人；n. 雄性动物；

例句
Logic had prevailed and he had abandoned the idea.
最终理智占了上风，他打消了那个念头。

sat

v. 坐(sit的过去式，过去分词)；n. SAT美国学术能力评估测

例句
He sat in an adjacent room and waited...
他坐在隔壁房间里等候。

behind

prep. （表示位置）在…的后面，支持，（表示顺序）在身后，（表示比较）落后于；adv. 在后面，向后，在后面较远处，（落）在后面；n. 〈口〉屁股；

例句
Ken was in the act of paying his bill when Neil came up behind him.
当尼尔从后面走过来时，肯正在付账。

desk

n. 书桌，办公桌，服务台，部门，（美）讲道台；adj. 书桌的，书桌上用的；

例句
He has been absent from his desk for two weeks...
他已经有两个星期没有坐在办公桌前了。

laboriously

adv. 艰苦地，费力地，辛勤地，（文体等）佶屈聱牙地；

例句
McGinnis pushed himself laboriously out of the chair and waddled to the window...
麦金尼斯吃力地从椅子上站起来，摇摇晃晃地走到了窗前。

writing

n. 文字，写作，文章，笔迹；v. 写（ write的现在分词），写信；

例句
...teaching the basics of reading, writing and arithmetic.
教授阅读、写作和算术的基础知识

with

prep. 和，跟，随着，关于，和…一致；

例句
A waiter entered with a tray...
侍者端着托盘进来了。

an

art. 一（在元音字母前代替不定代词a），一任一某一，一个；

例句
He started eating an apple...
他开始吃苹果。

army

n. 军队，陆军，团体，野战军；

例句
The army refused to accept orders from the political leadership...
军队拒绝接受政界领导层下达的命令。

issue

n. 问题，议题，（报刊的）期，号，发

例句
The Queen remains above criticism, apart from the issue of her tax liability...
抛开她的纳税义务不谈，女王一直无可指摘。

pen

n. 笔，笔尖，笔法，文笔，作家，围栏；vt. 写，把…关入栏中，关押，囚禁；

例句
Can I borrow a pen please? ...
我可以借支笔吗？