查询词典 optional

He wants to make SAT scores an optional part of the application for all 90,000 kids who want to go to U.C.

他希望能将SAT 作为每年想要进入加州大学的90，000名学生申请资格的一个可选项目。

This article analyzed characteristics and development trend of FCC gasoline in China, introduced the characters and plant effects of OCT-M and FRS FCC gasoline selective hydrodesulfurization process, especially the commercial application effect of the production of States Ⅲ and Ⅳ regulation gasoline. The commercial test results showed that OCT-M and FRS process were mature and credible, and had the characteristics of low pressure, low investment, convenient operation, low H2 consumption and high liquid yield. OCT-M and FRS process could offer refineries optional economical and flexible measure to produce States Ⅲ and Ⅳ regulation clean gasoline.

分析了我国FCC汽油的特点及发展趋势，介绍了OCT-M和FRS FCC汽油选择性加氢脱硫技术特点及中试效果，着重介绍了OCT-M和FRS FCC汽油选择性加氢脱硫技术生产国Ⅲ、国Ⅳ汽油的的工业应用效果，标定结果标明，OCT-M和FRS技术成熟可靠，具有装置压力等级低、投资省、操作方便、氢耗低、汽油产品收率高等特点，是我国炼厂生产国Ⅲ、国Ⅳ清洁汽油时可供选择的经济、灵活的解决方案。

Don not attempt to do something which you can not to do.

不要企图做那些办不到的事情。

The expression of CTGF and TNF-αweredetected by immunochemistry and the number of Clara Cells was calculated.

光镜下观察肺组织的病理变化，采用免疫组化染色观察肺组织中结缔组织生长因子和肿瘤坏死因子-α的表达和Clara细胞的数量。