在68℃下测试120小时之后，这些膜的质量损失小于7%的翻译：At 68 degrees c test after 120 hours, these films of quality loss is less than 7% 什么意思？中文翻译英文，英文翻译中文，怎么说？

青云英语翻译

At 68 ℃ under test 120 hours, these films is less than 7% mass loss

At 68 degrees c test after 120 hours, these films of quality loss is less than 7%

After 68℃ under tests for 120 hours, these membrane mass defect is smaller than 7%

The next test at 68 ° C After 1 hour, these membrane quality loss of less than 7 %

At 68 degrees c test after 120 hours, these films of quality loss is less than 7%