在下列各句的空白处填入一个最恰当的单词，使句子意思完整，语法正确。

1．一What ___________ do they speak?     一They speak Japanese．

2．Peter works in a big restaurant．He is a__________．

3．He doesn’t want to be a policeman，because it’s very _________．

4．Thanks a lot ___________ giving us so many books and nice toys．

5．There are a lot of beautiful __________ in Hawaii（夏威夷）in the US．