气焊、割胶管长度应不低于10m。
参考答案:对
The poor young man is ready to accept________help he can get. [ ]
A. whichever
B. however
C. whatever
D. whenever
已知某地土壤受到含镉废水污染,欲降低其危害,最有效措施是
A.降低土壤含水量B.降低土壤含氧量C.降低土壤pH值D.增加土壤含氧量E.升高土壤pH值