细胞分裂就是一个细胞分成两个细胞。下列叙述错误的是(    )

如图所示，物块A和B通过一根轻质不可伸长的细绳连接，跨放在质量不计的光滑定滑轮两侧，质量分别为m_A=2 kg、m_B=1 kg。初始时A静止与水平地面上，B悬于空中。先将B竖直向上再举高h=1.8 m（未触及滑轮）然后由静止释放。一段时间后细绳绷直，A、B以大小相等的速度一起运动，之后B恰好可以和地面接触。取g=10 m/s²。

    “My name's Jim Shelley and I'm an addict(有瘾的人)...”

    With these words I began to1the problem , the problem of my telephone addiction.I used to call people2, from the moment I woke up to the time I went to sleep.I3to be phoned ,I wanted to phone .Just one more call.

    It started socially-a few calls each day.It seemed4, just a quick chat.Gradually though, the5got worse. Soon it was6use, until, finally, addiction.

    And it began to affect my7. During the day I would disappear for8call .If I couldn't make a call , I spent the whole time waiting for the phone to ring .Getting more and more9,in the end , I would ring someone , then someone else,10myself just one more call.

    I was phoning people and11messages to make sure 12calls would see me through the day . I used to arrive at friend's homes and before the door was closed , go straight for the phone with the13“Is it OK if I just use the phone...?” At work ,I became14when my fellow workers tried to15me from using the phone.And one day I hit my boss (with the phone ).Finally , the police caught me16a phone box that had taken my last one pound coin, and I was17to see a psychiatrist (心理医生).

    I haven 't18a phone in the house for three weeks now , and it 's several days19 I used a phone box .I try not to watch TV because there are20 people on it making phone calls.My name is Jim  Shelley and I am an addict.