49.07+999×49.07
A．4 907
B．49 070
C．490 700
D．4 907 000
参考答案：B
聚硫密封剂(聚硫橡胶建筑密封膏)的主要技术性能较氯磺化聚乙烯建筑密封膏______。
What do you think of team spirit Do you think you are a good team player
