He was too excited _________. [ ]
A. speak
B. to speak
C. not to speak
D. speaking
答案:B
电渣压力焊时接头焊毕,应稍作停歇,方可回收焊剂和卸下焊接夹具;敲去渣壳后,四周焊包凸出钢筋表面的高度,当钢筋直径为25mm及以下时不得小于()mm;当钢筋直径为28mm及以上时不得小于6mm。
A、3;
B、4;
C、5;
D、8。