Read the following email message. Complete the email by filling in the blanks. Select the best choice for each blank.

Hi Alex, I'm so excited about our upcoming Arctic expedition next month! I've been researching the equipment we'll need, and I found this comprehensive guide from Arctic Outfitters Supply Co. Since this is your first polar adventure, I wanted to share some important information. First, we need to focus on proper layering. The guide recommends starting with 1 .... as base layers because they prevent hypothermia by keeping moisture away from your skin. For mid-layers, we should get either fleece or down jackets since we'll be facing temperatures between 2 ..... The outer shell is particularly important - it needs to be both waterproof and windproof. I like that they come with 3 ...., which will be crucial during our night explorations. For shelter, I'm thinking we should invest in a 4-season expedition tent rather than the emergency snow shelter kit because 4 ..... Also, don't forget that we need to bring special batteries for our electronic devices since 5 ..... By the way, we need to take their cold weather survival training before we can rent or purchase the more expensive equipment. They offer courses weekly, so we should sign up soon. Let me know what you think! Best, Jamie

Choose the best option.

Based on the email exchange between Jamie and Alex, it's clear that 1 ..... Jamie is particularly concerned about 2 .... for their expedition. According to the equipment guide, participants in arctic expeditions should consume 3 .... to maintain their energy levels in extreme cold.