凡岩石颗粒的长度大于该颗粒所属粒级的平均粒径（）倍者为针状颗粒；厚度小于平均粒径（）倍者为片状颗粒。
参考答案：2.4；0.4
I’ve been trying to phone Charles all evening, but there must be something wrong with the network; I can’t seem to_____.
A．get through
B．get off
C．get in
D．get along
请用不超过150字的篇幅，概括出给定材料所反映的主要问题。
