单选题 We were delighted to find the trees planted a year before ______ very tall.
A. growing B. being grown C. having been growing D. grown

【正确答案】 A

【答案解析】单词用法。and sb．/sth．doing sth．意为“发现某人/某物正在做某事”。根据此结构，排除选项D。由于句中分词与其逻辑主语之间是主动关系，因此可以排除B选项。按照逻辑关系，C也不正确。因此答案是A。