根据下面短文内容，在短文的空格处填上一个恰当的词，使短文完整、通顺．
When you talk with someone，you'll need to end your conversation at some point．And there are many reasons why you need to do that．Either you or the other person may need to continue an activity such （78） working or shopping．Or you may have run out of things to say．You just want to keep the conversation short．
But（79） do you end a conversation in a polite way？It may depend on where and how the conversation started．It may also depend on your relationship with the（80） person．If you already know that person，you can just say，"I need to run now．"Or you can say，"I'll catch you later．"You may also give a reason for ending the conversation．"I really need to go﹣my piano class starts in ten （81） ．"
Perhaps you just meet someone in a social situation，and you have a nice talk．But then you have to go．You can say，"It was nice meeting you．Maybe we can talk happily（82） sometime in the future．"
Another way to end a conversation is to make it easy for the other person to （83） ．If you see the other person is already not patient，you can say，"Well，I'm sure you have a lot to do today．"
You could use these （84） to end a conversation，and you should notice that others may also use them．（85） they do so，you should know that it's time for you to stop and get on with your day．
Maria （not do） exercise in the morning．She prefers doing it in the evening．
The graduation ceremony is on the way，there are some students （make） preparations for it．
My mother is （fortieth） years old，but she looks much younger than she really is．
To perform perfectly，we still need 8 pairs of white （trousers）．
There are 24 solar terms （节气） in China，and the Grain Rain（谷雨） is one of them．It falls on April 19 this year．
This solar term is called the Grain Rain because it is known for"rain"that helps the grain grow．From its name，we can guess it means a time of more rain．So if you go out in the next two weeks，you may need to bring an umbrella with you．
But this is a great time for planting crops．If you miss the time for planting during the Grain Rain，you will feel sorry later．So maybe you can try to plant some flowers or vegetables in your garden．When the spring rain falls，farmers begin to grow crops （庄稼）．Farmers often say，"Spring rain is as precious （珍贵的） as oil．"It brings farmers hope for a good year ahead．
There are also many interesting customs during the Grain Rain．In the northern part of China，people like to eat Chinese toon （椿芽） mixed with eggs．The food made during the Grain Rain tastes wonderful and is good for your stomach．In the southern part of China，the tea leaves are picked during the time．They are called Grain Rain tea，which is famous for its freshness and sweet smell．
（1）How many solar terms are there in China？ Twenty ﹣ four ．（ 24 ．）
（2）Is it necessary to take an umbrella during the Grain Rain？ Yes ， it is ．
（3）What is Grain Rain tea famous for？ Its freshness and sweet smell ．
（4）Why is it a great time for planting crops when the Grain Rain comes？ Because spring rain is as precious as oil and brings farmers hope for a good year ahead ． ．