17.完成句子：根据所给汉语意思，用单词或短语完成下列英文句子。
1．我爷爷七十岁了，但看起来依然帅气。
　　My grandfather is 70, but he still                                  ．
2．我们每年三月植树。
　　We plant trees                         every year．
3．如果你不知道事实，请保持沉默。
　　If you don’t know the truth, please keep                              ．
4．请访问我们的网站，来购买特别的礼物。
　　Please visit our website to                                         ．
5．多么有用的词典啊！
　　What                               they are!

18.根据下面对话中的情境，在每个空白处填入一个适当的语句，使对话恢复完整。
A: How was your weekend?
B:                               1                              ．I really enjoyed it．
A: Oh, did you go anywhere?
B: Yes．I went to a farm with my classmates．
A:                                2                              ．
B: Because we are doing an Experimental Education Project this year．
A: Experimental Education Project?           3                       ?
B: It’s a project for students to learn by practice．Students can learn something outdoors．
A: That’s interesting and meaningful．                   4                     ?
B: We learned to feed animals and plant vegetables．
A:Sounds great!                          5                         ．
B: You probably will．I hear all the schools will do the project．