Turn into singular/ Exercise

Rewrite the following general statements using plural nouns. Make sure that the verbs agree with their subjects. For example:
A bicycle is a convenient means of transportation.
Bicycles are a convenient means of transportation.

A secretary should be proficient in spelling and grammar.
Secretaries should be proficient in spelling and grammar.

1. A sportsman needs to remain calm under pressure.
2. An eagle has good eyesight.
3. A conference requires careful planning.
4. A rock is composed of minerals.
5. A potato is rich in starch.
6. An omelette is made of eggs and other ingredients.