第 1 题 · 六级
His parents immigrated to Canada when he was two, which changed the whole family’s life.
核心词：immigrate ˈɪmɪɡreɪt v. 移居入境
他两岁时父母移民去了加拿大，这改变了全家人的生活。
一般过去时主谓 + 介词短语 + when 时间状语从句 + which 从句短语 immigrate to短语 immigrate into
His parents ___ to Canada when he was two, which changed the whole family’s life.
第 2 题 · 六级
It can be tricky at first, but persevere, which is the key to real progress.
核心词：persevere ˌpɜːsɪˈvɪə v. 坚持，不屈不挠
一开始会有点棘手，但要坚持，这才是真正进步的关键。
一般现在时情态 + 主系表 + but 并列 + 祈使 + which 从句短语 persevere in短语 persevere with
It can be tricky at first, but ___, which is the key to real progress.
第 3 题 · 六级
The birds pecked at the breadcrumbs on the ground, which the children watched through the window.
核心词：peck pek v. 啄，啄食
鸟儿啄食地上的面包屑，孩子们隔着窗户观看。
一般过去时主谓 + 介词短语 + which 从句短语 peck at短语 a peck on the cheek
The birds ___ at the breadcrumbs on the ground, which the children watched through the window.
