Mary ________ go to London next year but she is not sure.
—I’m sorry I ________not get there on time. The traffic is heavy now.
—That’s OK. Take your time.
王刚同学在学习了解直角三角形及其应用的知识后,尝试利用所学知识测量河对岸大树AB的高度,他在点C处测得大树顶端A的仰角为45°,再从C点出发沿斜坡走2√10米到达斜坡上D点,在点D处测得树顶端A的仰角为30°,若斜坡CF的坡比为i=1:3(点E,C,H在同一水平线上).
(1)求王刚同学从点C到点D的过程中上升的高度;
(2)求大树AB的高度(结果保留根号).