问题
选择题
Mum，you really need to have a rest！You ________in the kitchen ever since you came back home three hours ago.
A．had worked
B．were working
C．have been working
D．worked
答案
答案：C
句意为：妈妈你真的需要休息了！从你三小时前回到家里，你就一直在厨房干活。强调从过去开始的某一动作一直延续至今并仍在进行时，用现在完成进行时。