如图是小红利用小瓶、橡皮塞和玻璃管自制的液体温度计。该温度计是根据液体热胀冷缩的规律来工作的。实际使用中发现该温度计玻璃管中液柱变化不明显，导致示数不准确。对此，请你提出一条改进的建议：____ 。

在横线里填上“<”、“>”、“=”。

800－4____800－40     750＋500____570＋700   1000－780____120＋100

根据下列短文内容，在短文后的空格处填上一个恰当的词，使短文完整、通顺。
Dear Bob,
   My name is Rich .I'm fourteen ____  old. I'm studying in a middle school. My school is nice and clean. There are 30 students in my class. It's ____  today. My classmates and I are ____  a good time on the beach. It’s a nice place .The water is blue and clear. Many birds ____  flying over the sea. Many people are ____  in the sea. Some boys are ____   football. Some people are lying____  the beach. A girl is ____  a book on a chair .Another girl is ____  photos. I ____  writing to you! What are you doing?
   I hope you can write to me soon.
   Best wishes!
                                                                                                                                                                                  Rich