we make general statement for animals,we use:Example
  • The elephant is a big animal.(Elephants are big animals./An elephant is a big animal.)
Then,how about others like vehicles,fruits ...etc.

  1. The bicycle has two wheels.
  2. A bicycle has two wheels.
  3. Bicycles have two wheels.
  4. The orange contains vitamin C.
  5. An orange contains vitamin C.
  6. Oranges contain vitamin C.
Which of the sentences are suitable?( pls give some guidelines)

Another question:
  1. James likes to eat oranges / the oranges / an orange.

which one to use? ( when saying James likes all the orange )
Native speakers normally use the plural for such common sentences:

Elephants are big animals
Bicycles have two wheels.
Oranges contain vitamin C.
James likes to eat oranges
.-- Here the plural is required: such a habit necessitates many oranges.

In more formal works, you will see the singular:

The picaresque novel was conceived by the anonymous 16th century author of 'La vida de Lazarillo de Tormes'.
Thank very much for your guidance.