his earnings were only half the amount___

问题描述:

his earnings were only half the amount___
1 as they used to 2 they used to 3 they used to be 4 they were used to
选择哪一个,及为什么,然后,aount又是什么意思

amount是数量 数额 大小的意思 这里就是 他挣的钱只是以前的一半了
我的话 选C they used to be 做amount的间接补语