W类Ⅱ型氯化聚乙烯防水卷材断裂延伸率应（）。
A.≥100%
B.≥125%
C.≥175%
D.≥250%
参考答案：D
______ the programme, they have to stay there for another two weeks. [ ]
A. Not completing
B. Not completed
C. Not having completed
D. Having not completed
在空气中，二氧化碳含量达到（）时，呼吸衰弱，精神不振，严重的可以因窒息而死亡。
A.15～20%
B.20～30%
C.30～35%
D.35%以上
