unnecessary

adj.

不必要的，多余的；无用的，无益的；无须；

unnecessary expenses不必要的开支

1. Don't involve yourself in unnecessary expense.
   勿做不必要的花费。
2. She often pothers herself over unnecessary details.
   她常在不必要的琐事上自扰。
3. All this is totally unnecessary.
   所有这些完全都是多余的。
4. Cut off the unnecessary twigs and branches.
   把多余的枝叶剪去。

Article makes simple errors and could cause unnecessary deaths
Laboratory markers in IBD: useful, magic, or unnecessary toys?
When are randomised trials unnecessary? Picking signal from noise
Use of Computed Tomography in Diagnosing Appendicitis: Redundant, Expensive, Toxic, and Potentially Unnecessary | The Journal of the...
"This most unnecessary & senseless war": Zachary Taylor Writes from Mexico
Hologram reconstructing apparatus and hologram reconstructing method
Sa1691 - Monitoring of Laboratory Parameters During Thiopurine Maintenance Therapy in Patietns with Inflammatory Bowel Disease: An U...
The NewReno Modification to TCP's Fast Recovery Algorithm
Projection type display system using a polarizing beam splitter
Polypharmacy in elderly patients