单项选择题

The population of America continues to grow because of ______.

A．its growing birth rates
B．the migration of persons from other countries
C．its good health condition
D．its longer life expectancy
<上一题 目录 下一题>
热门 试题

单项选择题
How could Dennis distinguish between a small ball and a large ball from a distance of 3 feet The large ball would produce ______.
A．a sharper sound
B．a softer sound
C．a higher-pitched sound
D．a louder sound
单项选择题
The author implies that the results of scientific research ______.
A．may not be as profitable as they are expected
B．can be measured in dollars and cents
C．rely on conformity to a standard pattern
D．are mostly underestimated by management
相关试题