Question

Waves of red light are about twice as long as _______ of blue light.

A．those

B．that

C．it

D．Ones

Answer 1

A

试题分析：考查指示代词。句意：红光的波长是蓝光波长的两倍长。在比较级中，指代比较对象时，单数用that，复数用those，这里的比较对象是waves，故选A。