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.
He drove fast and arrived an hour_____of schedule.
Copernicus maintained that the earth_____round the sun.
Bothofmybrothersarenowmarried，soIhavetwo_____.
Children who are over-protected by their parents may become_____.
_____you understand this rule ，you‘ll have no difficulty in dealing with such problems.
