2 sentences for 效力 (xiào​lì — effectiveness)

1. 该法律自颁布之日起具有法律效力。

   gāi fǎ​lǜ zì bān​bù zhī rì qǐ jù​yǒu fǎ​lǜ xiào​lì.

   The law takes legal effect from the date of its promulgation.

   Source: Dong Chinese Dictionary

2. 这份合同需要经过公证处公证才具有法律效力。

   zhè fèn hé​tong xū​yào jīng​guò gōng​zhèng​chù gōng​zhèng cái jù​yǒu fǎ​lǜ xiào​lì.

   This contract needs to be notarized by a notary office to have legal effect.

   Source: Dong Chinese Dictionary