Ⅳ.语法填空
阅读短文,在空白处填入一个适当的词或填入括号中所给单词的正确形式。
It's said that using certain skills is just like riding a bike. In other words,once they've been 1. (learn),you never forget them. And it's true that while we often forget facts, we can usually jump on a bike and ride away without 2. (think) about it.
But why can you still ride a bike even after not 3. (ride) one for years? The answer is that skills like riding or playing 4. instrument are part of procedural memory. It is a kind of long-term memory that performs different procedures. Once learnt 5. (complete),they're never forgotten.
This happens because procedural memory and declarative（陈述性的）memory are stored in 6. (difference) parts of the brain. Declarative memory is responsible for remembering information 7. names, dates, and events from your life. Studies say that the cells in the part of procedural memory can't 8. (easy) lose or get hurt. What's more, some research shows that the flow of blood in this brain area 9. (remain) stable,which helps keep the memory traces clear. So procedural memory isn't erased very often.
Now you know 10. we don't forget how to ride a bicycle. Can you name other skills that you're also unlikely to ever forget?

1. learned/learnt（两者皆可） 2. thinking 3. riding 4. an 5. completely 6. different 7. like 8. easily 9. remains 10. why

【分析】首先通读短文理解主旨，围绕程序性记忆的特点展开。逐个分析每个空的语法成分：1. 考查被动语态，主语skills是learn的承受者，需用现在完成时被动结构；2. without是介词，后接动名词作宾语；3. after是介词，后接动名词作宾语；4. 泛指乐器，元音音素开头的可数名词单数前用不定冠词an；5. 修饰动词需用副词；6. 修饰名词需用形容词；7. 用于举例需用介词like；8. 修饰动词需用副词；9. 主语为单数，一般现在时谓语用第三人称单数形式；10. 引导表原因的宾语从句需用why。
【解析】1. 句意为“一旦它们被学会，你永远不会忘记”，主语they指代skills，与learn是被动关系，现在完成时被动结构为have been + 过去分词，故填learned/learnt。2. without是介词，后接动名词作宾语，故填thinking。3. after是介词，后接动名词作宾语，故填riding。4. instrument是可数名词单数，此处表泛指，且以元音音素开头，故用不定冠词an。5. 此处修饰动词learnt，需用副词，complete的副词形式为completely，故填completely。6. 此处修饰名词parts，需用形容词，difference的形容词形式为different，故填different。7. 此处用于举例，意为“像……”，故填介词like。8. 此处修饰动词lose，需用副词，easy的副词形式为easily，故填easily。9. 主语the flow of blood是第三人称单数，全文为一般现在时，谓语动词用第三人称单数形式，故填remains。10. 此处引导宾语从句，结合上下文表“为什么”，故填why。
【答案】1. learned/learnt 2. thinking 3. riding 4. an 5. completely 6. different 7. like 8. easily 9. remains 10. why
【知识点】语法填空、动词形式变化、冠词与介词用法
【点评】本题为语法填空题型，侧重考查基础语法知识的运用，涵盖被动语态、非谓语动词、冠词、副词等考点，需结合语境分析语法成分，难度适中，适合巩固语法基础。
【难度系数】0.6