The Bubonic plague and the raids by Vikings.
ANSWER: IDENTIFY THE PROBLEM
EXPLANATION:
The first step Gillian should consider in exploration of her general problem-solving approach is the PROBLEM IDENTIFICATION.
However, since she doesn't have much knowledge about bicycle, identifying the source of the problem (i.e. tracing the source/cause of the new sound produced by her bicycle), will provide a template or background for her further problem solving procedures.
Copper
Iron
Nickel
It’s out of thoose 3
