Take another look at the sentence:
Saxe, Diane's horse, will let you know when she deserves another carrot or apple. She sticks out her tongue so that it __________ outside her mouth like a long, fat, pink worm.
Saxe's tongue rests outside her mouth. Thus, you need a form of lie. Since the sentence is present tense, you need the simple present form. Consult the table below or review the rules.
|Infinitive||Definition||Simple Present||Simple Past||Past Participle||Present Participle|
|to lay||to put something down||lay(s)||laid||laid||laying|
|to lie||to rest or recline||lie(s)||lay||lain||lying|