单选题
Notice to Office Personnel

Although this request was made on several occasions ______, we are still having instances in which the private vehicles of office personnel are blocking the loading and unloading area at the back entrance of the building. Personal vehicles must be kept ______ of that area, even for short periods.
If the problem continues, more severe ______ may be taken such as ticketing or towing. Please assist us in keeping it from reaching such extreme measures.
【正确答案】 C
【答案解析】[解析] 词汇：副词
1．这是一道词汇题，选项均为副词。
2．屡次要求是在过去发生的事情，因此要使用副词C．previously。
【正确答案】 A
【答案解析】[解析] 单词形态：形容词
1．这是一道单词形态题，选项均为clear的不同形式。
2．keep A clear of B意为“让A远离B”，宾语A移到主语的位置后，变为A be Kept clear of B，因此A为正确选项。
【正确答案】 C
【答案解析】[解析] 单词：名词
1．这是一道词汇题，选项均为名词。
2．空格内须填入一个和动词take连用的名词，take actions意为“采取措施”。rules或guidelines一般与follow和comply with连用。measure意为“措施”，名词measurements意为“测量”。