effective atomic mass

例句：

1. 1. The new policyis expected to be effective in reducing pollution.
   预计新政策能有效减少污染。
2. 2. The medicine is effective for treating headaches.
   这种药对治疗头痛有效。
3. 3. The new software is effective at organizing files.
   这款软件在整理文件方面非常有效。