电视机的显像管中，电子束的偏转是用电偏转和磁偏转技术实现的．如图甲所示，电子枪发射出的电子经小孔S₁进入竖直放置的平行金属板M、N间，两板间所加电压为U₀；经电场加速后，电子由小孔S₂沿水平放置金属板P和Q的中心线射入，两板间距离和长度均为L；距金属板P和Q右边缘L处有一竖直放置的荧光屏；取屏上与S₁、S₂共线的O点为原点，向上为正方向建立x轴．已知电子的质量为m，电荷量为e，初速度可以忽略．不计电子重力和电子之间的相互作用．

已知A（4，1，3），B（2，3，1），C（3，7，﹣5），点P（x，﹣1，3）在平面ABC内，则x=____ 

阅读下面短文，根据语境、音标或所给单词的提示，在每个空格内填入一个恰当的词，要求所填的词意义 准确、形式正确，使短文意思完整、行文连贯。

    The Chongyang Festival is a Chinese traditional festival. It is celebrated on the ninth day of the ninth lunar month. It's also____(call) the Double Ninth Festival.

    The festival started as____/'ɜ:li/ as the Warring States Period (475—221 BC) . It has a history of more than 1,700 years. Among the numbers from zero to nine, nine is the____(high) odd number (奇数). People believe that two "nines" meeting together stand for a long life. So it is a special holiday____Chinese people to show love and respect for their elders. They hold many____(kind) of activities in honor of old people, wishing them good____/helθ/ and a long life.

    The festival comes during the golden time of____/fɔ:l/. On the day, people traditionally drink chrysanthemum (菊花）wine, eat Double-Ninth Cakes____climb mountains. They also carry a kind of plant named dogwood. People in ancient times believed that ____plant could drive away evil (邪恶的）spirits and prevent them from____(catch) an illness in winter.