The time is drawing near  _____   food raised in space will directly benefit humans below.

1. A.
   where
2. B.
   when
3. C.
   whether
4. D.
   why

The time is drawing near  _____   food raised in space will directly benefit humans below.

 A．where B．when C．whether D．why

The time is drawing near         food raised in space will directly benefit humans below．

A．where            B．when           C．whether          D．why

The time is drawing near　　　　 food raised in space will directly benefit humans below.

A．where　　　　　　 B．when 　　　 C．whether 　 D．why