据英国《自然》杂志披露，位于纽约长岛的美国布鲁克海文国家实验室的相对论重离子对撞机再获重大发现：中外科学家探测检验到了迄今人类所知最重的反物质——反氦-4。这说明   

①物质具有可知性             ②人能够创造和认识物质

③意识具有能动作用           ④人能够分析和决定事物的性质

A．①③

B．②③

C．①②

D．③④

Culture shock is a feeling________most travellers experience in a foreign country________they

find the culture is quite different from that of their own.

A．that; which

B．that; where

C．when; where

D．which； which