判断对错．

0.123×0.02=0.0246．

三千零六亿五千万 写作____

放射性同位素钬的质量数A=166，质子数Z=67，则中子数与核外电子数之差为

设a=log₃10，b=log₃7，则3^a﹣b=（   ）

阅读短文，完成句子。
    Lychees grow in the south (南方) of China. They are small with red peel (果皮). Most people like to eat them, because they are sweet and full (充满的) of juice.  There is an old story about lychees. Yang Yuhuan loved lychees very much. Lychees have a lot of vitamin C. It is very important for people. Vitamin C can make children more healthy. So many parents often buy lychees for their children. Amy and her mum are in the fruit shop now. What fruit are they going to buy? Look! They are buying lychees
从文章中找到适当的单词或短语填空，完成句子。