题目内容：

根据所给提示，完成下列句子。每空一词，含缩略词。

1.You need to look up the word in the dictionary. (变否定句句)

   You ________ ________ to look up the word in the dictionary

2.I’d like to go to Guilin on vacation.（对划线部分提问）

Where _________ you _________ to go on your vacation? 

3.Linda takes care of her younger sister. (同义句)

   Linda ________ _________ her younger sister.

4.当他正走在街上时，看见事故发生了。

He saw the accident _________ while he was _________ down the street.