useful
英 ['juːsfʊl; -f(ə)l]
美['jusfl]
	    - adj. 有用的,有益的;有帮助的
 
英英释意
- 1. being of use or service;
 - "the girl felt motherly and useful"
 - "a useful job"
 - "a useful member of society"
 
- 2. of great importance or use or service;
 - "useful information"
 - "valuable advice"
 
- 3. capable of being turned to use or account;
 - "useful applications of calculus"
 
- 4. having a useful function;
 - "utilitarian steel tables"