下列各项中，哪项不是导致细胞癌变的致癌因子（   ）

实验室有如下器材：水、烧杯、量筒、天平、弹簧测力计、细线、小金属块、一个可以放入量筒中的小玻璃杯。选用上述器材可以测量小金属块密度（水的密度ρ水已知）。
（1）涂宇鸽同学的测量步骤是：①在量筒中倒入适量的水，体积为V1；②把金属块浸没在量筒水中，此时液面示数为V2；③用天平测出小金属块质量为m；④计算金属块的密度。请你指出涂宇鸽同学实验方案中的不足之处：_____________________________；
（2）请你再从提供的器材中选取器材，设计另一个实验方案测出小金属块密度。
选用器材：_____________________________________________
主要实验步骤：①___________________________________________________
②___________________________________________________。
所测金属块密度的表达式：ρ=______________________

下列属于内战爆发后，国民党真实情况的有(     )

①军事上节节失败        ②国统区人民安居乐业

③政治上孤立无助        ④经济上陷入崩溃境地

用方框中所给单词的适当形式填空

    We have a lot of trouble in our life, but we have to face them. When you are feeling unhappy or forget how great you are, there are six ways to make you____ good about yourself.

    (1)Look in the mirror (镜子) and say to____ ,“I'm a special person and there's no one in the world____ me. I can do anything!” It may not____ so good, but it really works!

    (2)Do something ____for someone. ____others always makes you feel good.

    (3)Smile! Be____ to people you meet. Look for the good things in your friends and family.

    (4)Learn something new! Have you always wanted to decorate your own room or learn____ to swim? Go for it! New challenges (挑战) are fun and give you a sense of accomplishment when you have finished.

    (5)Read and start a diary. Turn off the TV and let your imagination(想象) fly! If you have any thoughts, dreams or anything you want, ____them down! Writing always helps to express your feelings.

    (6)Stay with your family. We all ____ our family time. Talk with your Mum and Dad or maybe even your cousin.