Both of my brothers are now married ，so I have two_____.
A、sister-ins-lawB
“名词+副词/介词”或“副词/介词+名词”的复合名词，单数变复数时，只将中心名词变复数。如：on-look→on-looks;brother-in-law→brothers-in-law.
Hedidn‘tseemtomind_____themusicwhilehewasstudying.
_____youunderstandthisrule，you‘llhavenodifficultyindealingwithsuchproblems.
Hedrovefastandarrivedanhour_____ofschedule.
Mywalletisnowheretobefound.I_____itwhenIwasonthebus.
_____alltherepresentativesstillnotthere，themeetingwaspostponedforseveralhours.
