effective

US /əˈfek.tɪv/
UK /əˈfek.tɪv/
"effective" picture
1.

有效的, 有作用的

successful in producing a desired or intended result

:
The new policy proved to be very effective in reducing crime.
新政策在减少犯罪方面被证明非常有效
This medicine is highly effective against the flu.
这种药对流感非常有效
2.

生效的, 有效的

(of a law or agreement) coming into operation or effect

:
The new regulations will be effective from January 1st.
新规定将于1月1日生效
The contract is effective immediately.
合同立即生效