在稀硫酸中加入下列物质（V为加入溶液的体积），其对应曲线变化正确的是（  ）

By comparing with others, you will find your problems are not so terrible.（划线部分提问）
____  you find your problems are not so terrible?
It is interesting to send English messages to friends on a mobile phone.（改为感叹句）
____  interesting thing it is to send English messages to friends on a mobile phone!
It would be nice if we could get a room with a kitchen so we could cook our town meals.（改为同义句）
It would be nice if we could get a room____  a kitchen so we could cook our own meals.
Being a volunteer is great.（改为反义疑问句）
Being a volunteer is great,____ ?
The woman teacher asked the students “ Can you understand what I am saying?”（改为间接引语）
The woman teacher asked the students____  could understand what she was saying.

质量是50kg的人，以10m/s的水平速度在极短的时间内，跳上一辆迎面驶来的质量为200kg、速度为2m/s的车上，则跳后瞬间，车的速度大小为____m/s，方向为____（填“正”或“负”），（以车原来速度方向为正方向）．