钢筋混凝土预制桩采用重叠法制作时，重叠层数不得超过（    ）

A、<span style="FONT-FAMILY: &#39;Times New Roman&#39;,&#39;serif&#39;; FONT-SIZE: 14px">.</span><span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">二层</span><span style="FONT-FAMILY: &#39;Times New Roman&#39;,&#39;serif&#39;; FONT-SIZE: 14px">&nbsp;&nbsp;&nbsp;</span>

B、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">三层</span>

C、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">四层</span>

D、<span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px"><span style="FONT-FAMILY: 宋体; FONT-SIZE: 14px">五层</span></span>