The book 【is】 very interesting.
第三人称单数,现在时是直接it吗？看错了。The book 【itself】 is very interesting.这本书本身很有趣。Here's a card for you with our best ____(great)这句呢，很难Here's a card for you with our best gratitude (great)。这是一张卡，带着我们最高的感谢。