In fact, the process of giving up drug addiction for a determined person is easier than what he thought.

A．The metal is shaped into ingots.
B．The metal is separated into nickel and titanium.
C．The metal is drawn into a wire.
D．The metal is set in its desired curve or shape and heated briefly.

A．nitinol has its "memory" function because it is an alloy
B．the sun's rays are necessary to trigger the metal's "memory"
C．people have only begun to discover the many uses of nitinol
D．one problem with nitinol is that it often returns to its original shape at inopportune time