单选题
From: Peta Cavic To: Kyle Matthewson Subject: Lateness Kyle, I heard that you arrived late to the office again today. That's the sixth time this month that you have failed to make it into the office by 9 am, as (141) . If there is a reason for your lateness in this instance, please let me know. However, if you do not have a legitimate (142) , then this level of performance is simply unacceptable. As you know, I'm tied up at a conference all of today, but I think we need to officially address this issue tomorrow. I have been very disappointed with your conduct, so I (143) taking disciplinary action then. You have left me no choice. Peta Cavic
单选题
A. requires B. required C. requiring D. requirement
【正确答案】
B
【答案解析】as required表示“与要求的一致”，结构是<连词+过去分词>。可以认为是as you are required to doso省略了主语以及be动词。