任何非必需的变量都可以为空。
可以通过增加一个非必需的参数，轻松地改变这个函数的用途。
You can easily repurpose this function by adding a nonrequired argument.
基建工程，包括奥运会设施，仍按计划进行，但将削减非必需的支出。
Spending on infrastructure, including the Olympics, will continue as planned. But there will be cuts in “non-essential” spending.
这样的焦糖与拿铁的结合含有超出健康范围的糖分和人体非必需的卡路里。
This caramel confection hides an unhealthy dose of sugar and an unnecessary amount of calories.
天冬氨酸是一种非必需的酸性氨基酸，尤指从小的甘蔗和甜菜的糖蜜中提取的。
L - aspartic acid is a non - essential, acidic, genetically coded amino acid. Found especially in young sugar cane and sugar - beet molasses.
天冬酰胺是一种非必需的中性晶体氨基酸，许多植物里都有，易于水解为天门冬氨酸。
L - asparagine is a non - essential , neutrall , genetically coded amino acid . it is a crystalline amino acid , found in many plants , that is easily hydrolyzed to aspartic acid.
另外这些非必需的dna序列，甚至必需的编码区经常会受到长的非编码dna的干扰。
Besides these nonessential DNA sequences, even the essential coding regions are often interrupted by long stretches of noncoding DNA.
如果我们每年停止购买新出的、非想要或非必需的物品，需求会变小，工厂生产量也将缩减。
If we stopped purchasing new items every year that we don't really want or need, the demand is less, and factories will produce less.
下一次，索尼可能复制微软的做法，将PS 4剔除所有非必需的附件，而把价钱压倒最低。
Next time around, Sony will probably copy's Microsoft's routine, stripping the PS4 of all the non-essentials to get the base price down as low as possible.
但是，环境对此的影响非常关键，我们只能根据环境中确实存在的条件来定义必需或非必需的基因。
But it turns out the environment is very critical for this, and you can only define an essential or non-essential gene based on exactly what's in the environment.
他们测试在进化角度上必需的硒依赖蛋白是否比那些非必需的硒依赖蛋白对那些硒缺乏症更具抵抗力。
They tested whether selenium-dependent proteins that are essential from an evolutionary perspective are more resistant to selenium deficiency than those that are less essential.
谷酰胺一种非必需的氨基酸，c5h10n2o3，大量的含于动植物组织，大量生产用于医药和生化研究。
A nonessential amino acid, C5H10N2O3, occurring widely in plant and animal tissue and produced commercially for use in medicine and biochemical research.
比如通过“常组织”，把必需的物品与非必需的物品分开，将必需品的用量降低到使用最低下限，并把它放在一个便利之处。
For example, by "regular organization", the essential goods and non-essential items separately, will reduce the necessity to use the minimum amount of floor and put it in a convenient between.
在MeetingCreation对话框的后续附签中可以找到其他非必需的选项，其中包括新的Slides附签，它使得主持人可以更容易地上载幻灯片。
You can find additional non-required options on subsequent tabs in the Meeting Creation dialog box, including a new slides TAB that makes it easier for moderators to upload slides.
经济衰退时，消费者有可能会缩减玩具等非必需品的消费。
In a recession, consumers could be expected to cut down on nonessentials like toys.
孩子可能首先提及玩具，但要鼓励他们列出必需品，比如衣食住方面，以及非物质上的给予，比如爱、乐趣和关怀。
Children may first mention toys, but encourage them to list essentials like meals, shelter, clothing, and nonmaterial things like encouragement, love, fun and caring.
如果花销超过月收入，你需要减少非必需品的开销。
If your expenses exceed your income, you'll need to cut back on nonessential items.
signed/unsigned关键字是声明非浮点类型必需的。
The signed/unsigned keyword is required for non-floating point declarations.
改写命令行参数代码，以支持必需参数和非必需参数的更为合理的逻辑流。
Rework the command line arguments code to enable a more logical flow of required and non-required arguments.
请注意，消息部分的名称对于非接口类型的单个部分的消息也是必需的，并且可以按照第2部分中的描述从变量WSDL描述中推导出来。
Be aware that the message part is mandatory for single part but interface typed messages as well, and can be deduced from the variable WSDL description as described in part 2.
可能需要住院的目前患病人员应考虑推迟前往安哥拉、特别是前往威热的非必需旅行。
Persons with existing medical conditions who might require hospitalization should consider deferring non-essential travel to Angola, particularly to Uige Province.
尽管美国人花费了大量的钱在非必需品和服务上，他们也为他人买礼物开销很大。
Although Americans spend a great deal of money on unnecessary goods and services for themselves, they also spend a large amount on gifts for others.
巴斯认为，据此可得出简明扼要的结论：不要买入销售简单的非必需品的公司的股票，除非其股价已经非常低廉，远低于公允价值。
The simple conclusion, according to Buss: don't buy stock in those companies that sell simple discretionary items, except if you're going to go deep discount.
近来失业或保险金额不足的病人减少了就医次数，并且不愿接受带给医院丰厚利润的诊断检查和非必需手术。
Patient visits are decreasing, as many people are recently unemployed or underinsured, and profitable diagnostic procedures and elective surgeries are declining, according to the report.
没有哪个时候能比假期更适合研究美国和世界各地消费者的非必需品(与食品和住房等必需品相反)消费情况。
What better time than the holidays to look at how consumers — in the U.S. and around the world — spend their discretionary dollars (as opposed to outlays on necessities like food and housing).
正因为我们不需为饮水付钱，多出的钱可以用来购买钻石等非生活必需品。
Because we do not have to worry about paying for water, this gives us money to pay for things like diamonds, that do not fall out of our faucets.
正因为我们不需为饮水付钱，多出的钱可以用来购买钻石等非生活必需品。
Because we do not have to worry about paying for water, this gives us money to pay for things like diamonds, that do not fall out of our faucets.
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