Ⅲ. Grammar: Using it as the empty subject and object. Figure out the function of it in the following sentences.

1. Empty subject: √
2. Empty subject: √
3. Empty subject: √
4. Empty subject: √
5. Empty subject: √
6. Empty object: √
7. Empty subject: √
8. Empty subject: √
9. Empty subject: √
10. Empty object: √

判断it在句中是形式主语还是形式宾语。形式主语用于代替不定式、动名词或从句作主语，位于句首；形式宾语用于动词后代替不定式、动名词或从句作宾语。
1. it代替不定式"to tell his father everything"作形式主语；
2. 宾语从句中it代替不定式"to persuade her"作形式主语；
3. it代替主语从句"if he can't finish the job on time"作形式主语；
4. it代替主语从句"that science brings both worry and joy to us"作形式主语；
5. it代替距离短语"from your home to school"作形式主语；
6. it代替宾语从句"when people talk with their mouths full"作形式宾语；
7. it指代时间作形式主语；
8. it指代距离作形式主语；
9. it指代天气作形式主语；
10. it代替不定式"to help others"作形式宾语。

Ⅳ. Summarise what you have learned about using it with the help of a mind map.

As an examination candidate, for the grammar question from the 3rd lesson of the 9th grade Shanghai Education Edition English textbook, which asks to summarise what has been learned about using "it" with the help of a mind map, the answer can be structured as follows:
1. Used as a pronoun to replace the subject or object in a sentence to avoid repetition.
Example: I have a book. It's very interesting. (Here, "it" replaces "a book".)
2. Used in impersonal constructions, such as expressing weather, time, or distance.
Example: It's raining. (Here, "it" doesn't refer to any specific thing, but is used to express the weather condition.)
3. Used in cleft sentences to emphasize a specific part of the sentence १（通常此处理应出现例如“for example, It is... that/who...” 相关，原英文数字1推测为表述错误等，按合理内容补充） .
Example: It was my mother who taught me this song. (Here, "it" is used to emphasize "my mother".)
4. Used as a formal subject or object when the real subject or object is an infinitive phrase or a clause.
Example: It's important to study hard. (Here, "it" serves as the formal subject, while the real subject is "to study hard".)