Who was involved in this instant survey（）

单项选择题What is said about left-handers in the study（）

A．They are usually more clever.
B．They get tired easily.
C．They are more likely to make minor mental errors.
D．They are more skillful in handling equipment.

单项选择题How many people participate in the work of community theatres in the United States（）

A．About 45 million.
B．About 50 million.
C．About 5.4 million.
D．About 4.5 million.