whose novels always began with: 'the case of the . . .'?

Questions

[science and technology] what is the gestation period of a cow?

[science and technology] what is the name of the minute organisms found drifting near the surface of seas and lakes?

[science and technology] what is the name of the instrument used for measuring humidity in the air?

[science and technology] what fruit is considered to be the most nutritious?

[science and technology] the deficiency of which vitamin causes scurvy?