在轨道坡度小于或等于5‰时,人力推车同向间距不得大于10米。
参考答案:对
为了探究液体内部的压强与哪些因素有关,小王同学用两只相同的封闭小木桶做实验。他在小木桶内分别装满水和盐水,在小木桶上各插上一根很细的玻璃管。当他从上方利用漏斗向玻璃管中灌水或盐水时,实验的现象如图(a)、(b)、(c)所示。请根据实验现象及相关条件,归纳得出初步结论。(ρ水<ρ盐水)
①比较(a)、(b)两图可知:_________________________________________________;
②比较(b)、(c)两图可知:_________________________________________________;
--These days I can only sleep for four or five hours at night as I’m too busy with my research work.
--If you keep going on like that, you are sure to ______ sooner or later.
A.break down
B.get down
C.calm down
D.put down