The blank needs to be filled by a unit. Whenever a unit is preceded by a number and followed by a noun, the unit needs to be singular. Option 2 & 3 are plural. Hence, option 1.

The correct usage is option 1, as plural of poultry is 'poultry', not 'poultries'.

The correct option is option 2.

The correct replacement for 'children' is 'offspring'.

We enjoy reading either 'books' or 'literature'. Hence, option 2, and not option 3, is the correct answer.

Words like 'mischief' and 'voilence' are always used in singular. Hence, option 1.

The blank needs to be filled by a unit. Whenever a unit is preceded by a number and followed by a noun, the unit needs to be singular.

Word 'michief' is always used in singular. 'Brave' (noun) is an incorrect option, as we need an adjective here.

Option 2 is the correct usage. 'Alm' is an incorrect usage.

We wear one shirt and two shoes at a time. Hence, option 3 & 4 eliminated. Word 'trouser' is an incorrect usage. Trousers are a pair (two legs), same as scissors are. Hence, option 2.

'Datas' is incorrect usage. Plural of 'datum' is 'data'. Some words like 'machinery', 'furniture', 'information', etc are always used in singular. Hence, option 1.

Some words like 'alms', 'summons', etc are always used in plural form, but they are singular in sense.

Some words like 'machinery', 'furniture', 'information', 'scenery', etc are always used in singular.

Auxilary 'is' in the sentence needs a singular subject. Option 3 & 4 are plural, and hence, deleted. Some words like 'alms', 'summons', 'billiards', etc are always used in plural form, but they are singular in sense.

Auxilary 'is' in the sentence needs a singular Option 3 & 4 are plural, and hence, eliminated. Some words like 'machinery', 'furniture', 'information', 'poetry', etc are always used in singular.