圆型竖曲线的半径是根据哪两个条件拟定的?
参考答案:旅客舒适条件、运行安全条件。
— Do you speak English after school?
— When we practice speaking English, we often end up _____ in Chinese. [ ]
A. to speak
B. speaking
C. spoken
D. speak
户外烧烤应注意哪些防火内容?