水解聚丙烯腈钙盐具有抗温、抗盐、抗钙能力强的特点。
参考答案：对
30. ---__________you got to know so much about the pop group in America?
---Through the Internet.
A．How was it
B．What was it
C．How was it that
D．What was it that
卸落浆砌石拱桥的拱架，须待砂浆强度达到设计强度标准值的（）。
A.70%
B.75%
C.80%
D.85%
