手工电弧焊接接头单面焊时，必须保证（）不小于0.7倍的板厚。
A.焊缝厚度
B.焊缝熔深
C.焊缝余高
D.焊缝计算厚度
参考答案：D
患者，男，5岁，绕脐腹痛，嗜食异物，大便时曾排出蛔虫，下肢出现湿疹，宜首选（）
A.槟榔
B.麦芽
C.鸡内金
D.使君子
E.苦楝皮
It is said that the iron and steel works _____not far from here, but now there ______no means of finding it out.
A．is ; is
B．are ; are
C．are ; is
D．is ; are
