A．It is damaged by extremely dry weather.
B．It loses water to stronger trees.
C．Insects destroy the tree' s bark.
D．Certain beetles introduce a fungus to the tree.
A．By controlling the carriers of the disease.
B．By growing a stronger kind of the elm.
C．By watering infected elm trees.
D．By cutting down all infected elms.
A．They painted in their spare time.
B．They lacked formal art training.
C．They used a more traditional approach to color.
D．They followed rules established by art schools.