SAT文法知识系列栏目说明：每期分享3-5个文法知识点，帮助大家更好地备考SAT。
一、标点符号
1. 含义：
句中的标点符号使用要规范。
2. 类型：
（1）逗号符号
3. 用法 - 不可分隔
（1）主语和谓语之间、谓语和宾语之间都不能用逗号隔开。
例句1: Tom, gets a higher mark.（错误）
解析：本句中的主语Tom和谓语gets之间不能用逗号隔开，所以需要去掉逗号。
改为：Tom gets a higher mark.
例句2: Tom (known as a gifted boy), gets a higher mark.（错误）
解析：本句中虽然有known as a gifted boy作为插入语修饰Tom, 但改变不了主语Tom和谓语gets之间不能用逗号隔开事实，所以需要去掉逗号。
改为：Tom (known as a gifted boy) gets a higher mark.
例句3: Tom gets, a higher mark.（错误）
解析：本句中的谓语gets和宾语a higher mark之间不能用逗号隔开，所以需要去掉逗号。
改为：Tom gets a higher mark.
例句4: Tom believes, that he can fly.（错误）
解析：本句中的谓语believes和that引导的宾语之间不能用逗号隔开，所以需要去掉逗号。
改为：Tom believes that he can fly.
（2）副词与形容词之间、形容词与名词之间不能用逗号隔开。
例句5: China is one of the progressively, developing countries.（错误）
解析：副词progressively与形容词developing之间不能用逗号隔开，所以需要去掉逗号。
改为：China is one of the progressively developing countries.
例句6: China is one of the progressively developing, countries.（错误）
解析：形容词developing与名词countries之间不能用逗号隔开，所以需要去掉逗号。
改为：China is one of the progressively developing countries.
题目检测
题目检测 1
Mary Smith (known as a prodigy in her neighborhood), has already studied calculus course since she was six years old.
A. NO CHANGE
B. ,(known as a prodigy in her neighborhood),
C. (known as a prodigy in her neighborhood,
D. (known as a prodigy in her neighborhood)
解析：通过逗号看出是标点符号中是否可以分隔的考点，根据“主语和谓语之间不能用逗号隔开”的原则，主语Mary Smith与谓语has studied之间不能用逗号隔开，所以排除A/B/C，所以选D。
题目检测 2
Peter Watson who developed an effective drug, saved millions of people suffered from chronic diseases.
A. NO CHANGE
B. ,an effective drug, saved
C. an effective drug saved
D. ,an effective drug saved
解析：通过逗号看出是标点符号中是否可以分隔的考点，根据“主语和谓语之间不能用逗号隔开”的原则，主语Peter Watson虽然有who引导的从句修饰，但其不能与谓语saved之间用逗号隔开，所以排除A和B；又根据“谓语和宾语之间不能用逗号隔开”的原则，从句中的谓语developed与宾语an effective drug之间也不能用逗号分隔，所以排除D，所以选C。
题目检测 3
Maria Sharapova, one of the most talented tennis athletes, won, the WTA championship.
A. NO CHANGE
B. athletes won, the WTA
C. athletes, won, the WTA,
D. athletes, won the WTA
解析：通过逗号看出是标点符号中是否可以分隔的考点，根据“主语和谓语之间不能用逗号隔开”的原则，one of the most talented tennis athletes是插入语修饰主语Maria Sharapova，所以是双逗号，故排除B；又根据“谓语和宾语之间不能用逗号隔开”的原则，谓语won与宾语the WTA championship之间也不能用逗号分隔，所以排除A和C，所以选D。
题目检测 4
Compared with other countries in the past four decades, China is one of the fast growing countries in the world.
A. NO CHANGE
B. fast, growing countries
C. fast growing, countries
D. fast, growing, countries
解析：通过逗号看出是标点符号中是否可以分隔的考点，根据“副词与形容词之间不能用逗号隔开”的原则，副词fast修饰形容词growing，所以不能用逗号隔开，故排除B和D；又根据“形容词与名词之间不能用逗号隔开”的原则，形容词growing和名词countries之间也不能用逗号分隔，所以排除C，所以选A。
