1. The best estimates are that the temperatures will rise y 2-3℃ in this century, causing considerable problems, at a total cost of US $5,000 billion.(剑5, Test 1 passage 3)
分析：本句主句为“The best estimates are that…”; “that the temperatures will rise y 2-3℃ in this century, causing considerable problems, at a total cost of US $5,000 billion.”为that引导的表语从句，做are的表语; “causing considerable problems”为现在分词短语做伴随状语。
2. Despite the intuition that something drastic needs to be done about such a costly problem, economic analysis clearly show it will be far more expensive to cut carbon dioxide emissions radically than to pay the costs of adaptation to the increased temperatures.(剑5, Test 1 passage 3)
分析：本句中“Despite the intuition that something drastic needs to be done about such a costly problem”为介词短语作让步状语;其中“that something drastic needs to be done about such a costly problem”为that引导的同位语从句，做the intuition的同位语;“economic analysis clearly show it will be far more expensive to cut carbon dioxide emissions radically than to pay the costs of adaptation to the increased temperatures.”为本句的主句，其中“it will be far more expensive to cut carbon dioxide emissions radically than to pay the costs of adaptation to the increased temperatures.”为宾语从句，做show的宾语，引导词省略，it为形式主语，后面的不定式为真正的主语。
3. It is crucial that we look at the facts if we want to make the best possible decisions for the future. (剑5, Test 1 passage 3)
分析：本句主句为“It is crucial that we look at the facts”; 其中It为形式主语，“that we look at the facts”为that引导的主语从句，是该句子真正的主语;“if we want to make the best possible decisions for the future”为if引导的条件状语从句。
4. Some are ‘thermoplastic’, which means that, like candlewax, they melt when heated and can then be reshaped.(剑5, Test 2 passage 1)
分析：本句的主句为“Some are ‘thermoplastic’”; “which means that, like candlewax, they melt when heated and can then be reshaped.”为定语从句，做‘thermoplastic’的定语，关系词为which; 在此定语从句中“that, like candlewax, they melt when heated and can then be reshaped.” 为that引导的宾语从句，做means的宾语;“when heated”为过去分词短语做状语，做they melt的时间状语。
5. Baekeland’s interest in plastics began in 1885 when, as a young student in Belgium, he embarked on research into phenolic resins, the group of sticky substances produced when phenol (carbolic acid) combines with an aldehyde (a volatile fluid similar to alcohol). (剑5, Test 2 passage 1)
分析：本句的主句为“Baekeland’s interest in plastics began”; in 1885为时间状语，而“when, as a young student in Belgium, he embarked on research into phenolic resins”为定语从句，做1885的定语，关系词为when; “the group of sticky substances”为phenolic resins的同位语;“produced when phenol (carbolic acid) combines with an aldehyde (a volatile fluid similar to alcohol”为过去分词短语做定语，做the group of sticky substances的定语，而“when phenol (carbolic acid) combines with an aldehyde (a volatile fluid similar to alcohol).”为when引导的时间状语从句。
