It is only recent years that man found that the protection of our environment is no small matter to our lives．
【正确答案】
A
【答案解析】解析：It is that是一个强调句型。it is only recent years意为“直到最近几年”。 no small matter to our lives直译为“对我们的生存来说不是一件小事”，A选项翻译成“对我们的生存至关重要”更加简练、准确。