No one can walk the wire without a bit of fear unless ________ very young.

A. having been training   B. trained      C. to be trained    D. being trained

No one can walk the wire without a bit of fear unless ____ very young.

A. having been trained 　　 B. trained　 C. to be trained D. being trained

No one can walk the wire in the air without a bit of fear unless ______ very young.

1. A.
   having trained
2. B.
   trained
3. C.
   to be trained
4. D.
   being trained

No one can walk the wire in the air without a bit of fear unless ______ very young.

No one can walk the wire in the air without a bit of fear unless ______ very young.