第 1 题 · 四级
He tied the rope into a knot, which kept the boat from moving away.
核心词：knot nɒt n. 结；v. 打结
他把绳子打成一个结，让船不能漂走。
一般过去时tie into a knot + which 从句 + keep…from…短语 tie a knot短语 keep…from doing
He tied the rope into a ___, which kept the boat from moving away.
第 2 题 · 四级
Stir the soup gently, which helps the salt spread through it evenly.
核心词：stir stɜː v. 搅拌；激起
轻轻搅拌汤，让盐均匀分布。
一般现在时祈使句 + which 从句 + help sth do短语 stir the soup短语 stir up
___ the soup gently, which helps the salt spread through it evenly.
第 3 题 · 四级
The exact number is not known, but an approximate figure is about ten thousand.
核心词：approximate əˈprɒksɪmət adj. 近似的
确切数字未知，但大约是一万。
一般现在时but 并列句 + approximate figure短语 an approximate figure短语 approximate value
The exact number is not known, but an ___ figure is about ten thousand.
