用括号中所给单词的适当形式填空。
⑴I take my dog out for a walk ________ (one) a day.
⑵There’s somebody ________ (hide) behind the door.
⑶Sandy does her homework ________ (careful) than Tom.
⑷There are many tall ________ (build) on both sides of the street.
⑸Why does she look ________ (worry) today? What’s the matter?