铸铁材料广泛用于机床床身、机座等部位是因为其（）。
A.抗拉性能好
B.抗压性能好
C.弹性好
D.韧性好
参考答案：B
Eating too much fat and sugar can________heart disease and high blood pressure. [ ]
A. result from
B. attend to
C. devote to
D. contribute to
折射望远镜的放大率=（）
