解析：C　细节理解题。根据文章最后一段可知，作者想通过这篇文章传达一个信息：我们不知道未来和意外哪一个会先来，所以要珍惜当下，珍惜眼前人。

　　B

　　 Some child development researchers have suggested that babies can start recognizing sign language at the age of six months. While this may seem like an idea that can't fail, there are several factors to consider when thinking of introducing sign language into your baby's development.

　　 Baby signing is made up of simple gestures closely linked to the word/action being signed. It is important to start with very basic signs, for those ideas your child is familiar with, such as "eat"， "drink" and "milk"．

　　 It is recommended to start this signing roughly between the ages of 6­9 months, and follow your baby's lead when it comes to devising gestures, for example observe what interests your baby and develop actions for these. It is important to always speak when signing, and never attempt it in silence. Equally, speaking slowly and clearly, but with a natural tone, as well as keeping each sentence limited to one particular sign are key factors to stick to.

　　 Signing can be quite beneficial when a child wants to communicate at an age when their spoken language is simply not developed enough to make this happen. However, although there is no evidence that signing delays (耽搁) the development of a child's speech, it is a concern for many parents that signing will take over the development of their child's speech, causing problems later in their years. Research has suggested that babies learning sign as a first language produce their first signs slightly earlier than babies produce their first spoken words, therefore it can be a worry that sign language becomes the standard for children, even as their speech develops.

　　 On the positive, sign language can help baby's understanding and their expression of language before their development is at a level when they can physically speak it; therefore it can help beat frustration (挫折), alongside allowing you to meet your baby's needs quickly, causing less upset.

　　【文章大意】　本文为说明文，题材为家庭教育类。研究表明，婴儿在六个月时已经具备了理解手势语的能力，但父母们应当如何在婴儿的语言能力形成之前利用手势同婴儿有效沟通呢？本文就此给出建议。

5. What does the underlined word "devising" in Paragraph 3 mean?