Misc: What is dennis the menace's surname?

Questions

A famous stallion will, on retirement, command an impressive stud fee for servicing approved mares. Specialist stud-farms house one or more stallions, each of which is allowed to service about ---------- per season.?

A female mouse may spawn as many as ten litters of eight to ten young during her lifetime - which is generally less than a year. The gestation period is three weeks, and the young mice reach maturity in only ----------?

A fox litter is typically 10 to 15 ----------?

A full-grown ---------- may be 8 feet high at the shoulder and weigh almost a ton.?

A garter snake can give birth to ----------?