Đọc bài và trả lời câu hỏi dưới ạ (1 câu ạ): Dear Elizabeth, Im sending this postcard to you from Canada and hope it finds y

Đọc bài và trả lời câu hỏi dưới ạ (1 câu ạ):
Dear Elizabeth,
Im sending this postcard to you from Canada and hope it finds you doing well. Ive been in Canada for almost a year studying science at the University of Toronto. Things are going great for me here. I got a job as a teacher assistant researching climate change and its effects on the ecosystem. Last month we went to Lake Superior and took water samples to test the pollution levels. The weather here is so cold! We took a ferry to cross the water in a snow storm, and the wind was blowing so hard it was making the boat rock from side to side. It was an exciting adventure.
Next week is the winter holidays. Im planning on going skiing for the first time. I wish you could be here so we could spend time traveling and taking photos. Canada is such a beautiful country. I think you would really enjoy visiting.
Your friend, Tom
(35) Last month, he took a ____ across the lake to test the water pollution levels in Lake Superior.