焊缝符号一般由______和______组成,必要时还可以加上______、______和______。
参考答案:基本符号;指引线;辅助符号;补充符号;焊缝尺寸符号
By using ears one can tell the direction ____ a sound comes.
A.in which
B.from which
C.with which
D.through which
精索鞘膜积液
A.X线腹片见肠壁串珠状透亮区B.X线腹片见上腹部双泡征C.X线腹片见上腹部三泡征D.X线腹片见一大液平E.X线腹片见腹腔空白伴双泡征