试样的制备通常应经过破碎、过筛、混匀、缩分四个基本步骤。( )
参考答案：对
------ How was your trip to Yungang Caves during your National Day holiday?
-------- Wonderfully! I’ve never had _______ one before．
A．a pleasant
B．a more pleasant
C．a most pleasant
D．the most pleasant
结合水
