铝合金缸体、缸盖比铸铁的更难焊接,最好的焊接方法()。
A.亚氟焊
B.CO2保护焊
C.乙炔焊
D.钎焊
参考答案:A
Everyone will go through life's stages of ups and downs, _____ self-respect plays a key role in the maturity
of a person. [ ]
A. when
B. which
C. as
D. that
亚硝酸盐中毒的特效解毒剂是()。
A.亚甲蓝
B.二巯基丙磺酸钠
C.牛奶
D.乳糖
E.葡萄糖