I think no bed here is big enough for hi

在城A的西南方向上有一个观测站B，在城A的南偏东15°的方向上有一条笔直的公路，一辆汽车正沿着该公路上向城A驶来．某一刻，在观测站B处观测到汽车与B处相距31km，在10分钟后观测到汽车与B处相距21km．若汽车速度为120km/h，求该汽车还需多长时间才能到达城A？

下列句子的标点符号使用正确的一项是（   ）

A．有诗云：“长桥驾彩虹，往来便是井。日中交易过，斜阳乱人影”。

B．未到婺源，婺源是一个奇迹，来到婺源，婺源有许多奇迹。

C．翻开《红楼梦》，我们会为曹雪芹当年在悼红轩中“披阅十载，增删五次”而感动。

D．北京的美食有哪些？您一定会说出一大串儿：什么豆汁儿啦、炒肝啦、爆肚啦……

在城市道路系统规划中，大城市主干路的道路网密度是( )km/km²。

A．0.4～0.5
B．0.8～1.2
C．1.2～1.4
D．3～4

Man: I’d like to sign up for some voluntary work with the environment council. I hear it’s a great way to connect with the community.Woman: It sure is, but you’ll have to put in a lot of hours. So you must leave some room in scheduling your time.Question: What does the woman imply

A．Voluntary work can help the man establish connections with the community.

B．The man’s voluntary work has left him little room in his schedule.

C．Voluntary work with the environment council requires a time commitment.

D．A lot of people have signed up for voluntary work with the environment council.

动作技能的特点是动作对象的物质性、动作进行的外显性及动作结构的简缩性。