Read the following passage and answer the question below.
Liam zipped up his rucksack with a final, decisive tug.
Inside, packed with military precision, were his waterproof trousers, a Tupperware box of carefully cut sandwiches, and a brand new bird-watching guide.
He had been checking the weather forecast for Pembrokeshire every hour since Monday.
He glanced at the clock; it was only 6:00 a.m., but his coach wasn't due to leave the school until 8:30 a.m.
He paced to the window, peering through the curtains at the pre-dawn gloom, hoping to see the first signs of a clear sky.
Based on the passage, how is Liam most likely feeling about his school trip?