您要查找的是不是：
- optional signed constant 任意符号常数
- An optional sign specifier that forces a sign (- or +) to be used on a number.By default, only the - sign is used on a number if it's negative. 非必选项指定填充，说明使用何种字符来填充结果成为适当的字符串长度，它可以是个空白字符或是0(字符0)，它默认上是使用空白来填充。
- He persuaded her to sign the document by guile. 他用欺骗手段说服她在文件上签字。
- The insurance cover is optional. 保险范围可以随意选择。
- The patrolman signed for them to halt. 巡逻警察做手势要他们停下。
- A 4-speed automatic transmission is optional. 四段自动变速器是可自由选择的。
- He signed on as a sailor for three years. 他签约受雇当海员3年。
- An optional academic course or subject. 选修的科目选修课程或课题
- He signed away his share in the property. 他签字放弃他在那笔财产中应得的一份。
- He signed up for a voyage to India. 他签约参加到印度的航行。
- She signed her name to the document. 她在文件上签了名。
- The cassette player is an optional extra in this make of car. 这种型号汽车如需盒式磁带唱机费用另计。
- The buyer and seller have signed the contract. 买卖双方已经签定了那项合同。
- The Government has signed a treaty with Moscow. 政府已与莫斯科签了一项条约。
- The king signed the instrument of abdication. 国王签署了逊位的文告。
- The team signed on ten more players yesterday. 该队昨天又签约雇用了十名选手。
- You must do it; you have little option. 你必须做,你没有选择的余地。
- It is at your option to stay or leave. 去留随你的便。
- John signed on yesterday and will start work on Monday. 约翰昨天签约受雇，将从星期一开始工作。
- You must do it; you have no option. 你必须做，你没有选择的余地。
