单选题 · 选择一个答案
Your road currently has a 50 km/h limit. A 70 km/h sign is ahead. Assuming your vehicle has no lower limit and conditions are safe, when may you begin accelerating above 50 km/h?
当前路段限速每小时50公里，前方有70公里限速牌。假设车辆没有更低限速且路况安全，何时才可开始加速超过50公里？
The higher limit takes effect at the sign. Keep within 50 km/h until you have passed it.
较高限速从标志处开始生效；驶过该标志前仍须保持在每小时50公里以内。
阅读相关知识
A higher posted limit is permission up to a maximum, not a requirement to accelerate. Lower vehicle limits and unsafe weather, traffic or road conditions still govern your speed.
较高限速只是允许的上限，不要求加速。车辆自身较低限速以及天气、车流和道路安全条件仍须遵守。