凸形竖曲线最小半径需要满足()和()的要求。
参考答案:离心加速度(或离心力)、行车视距
The janitor's long service with the company was________a present.
A.confirmed by
B.recorded with
C.appreciated by
D.acknowledged with
普通甜椒的种子,在太空条件下,引起 _____ 发生变化,经_____ 成为太空椒。