题目

随着颗粒、粉尘的不断侵袭，口罩、空气净化器也开始热销，伴之而来的是清洁概念悄然爬上投资者的案头，空气净化器、口罩及其原材料、环保产业的脱硫脱硝等都成为投资者津津乐道的话题。这说明（ ）①认识对象的改变总是带来人们认识的改变 ②意识活动具有主动创造性和自觉选择性③人们的认识活动能够直接地改造客观世界 ④客观实践的变化推动人们认识的变化发展A.①② B.①③ C.②④ D.③④— Did you return the book to me? Why can’t I find it anywhere? — ________. You were writing a letter at your desk at that time. A．I will give it to you B．I did give it to you C．I had given it to you D．I do give it to you