现代项目评估实践强调（）。
A.以静态分析为主
B.以定性分析为主
C.以价值量分析为主
D.以历史统计分析位主
参考答案：C
手工电弧焊要求弧焊电源应具有陡降的外特性，这样焊接过程中电弧长度发生变化时（）变化较小。
Oh, you have come back! I ______ I could see you again in such a short time. [ ]
A. haven't thought
B. didn't expect
C. don't expect
D. haven't been told
