1. Question #1, the third sentence:
Maybe a_b should be $ and null should be 0.
2. Question #10, the third sentence:
g1 should be g2.
a_b defaults to a null value.
Maybe a_b should be $ and null should be 0.
2. Question #10, the third sentence:
Reference one points to g1 and reference two is null.
g1 should be g2.