第 1 题 · 四级
The old hut was built from cheap materials, which are impermanent and easy to wear out.
核心词：impermanent ɪmˈpɜːmənənt adj. 非永久的，暂时的
那座旧小屋用廉价材料建成，不耐久且容易破损。
一般过去时被动语态 + which 从句（主系表）短语 impermanent materials短语 an impermanent state
The old hut was built from cheap materials, which are ___ and easy to wear out.
第 2 题 · 四级
The connexion between the two ideas is not obvious, which the teacher explained with examples.
核心词：connexion kəˈnekʃn n. 连接，联系（connection 的英式拼法）
这两个观点之间的联系并不明显，老师用例子作了解释。
一般现在时主系表 + 介词短语 + which 从句短语 the connexion between短语 a close connexion
The ___ between the two ideas is not obvious, which the teacher explained with examples.
第 3 题 · 四级
A large portion of the budget goes to education, which the government has promised to keep.
核心词：portion ˈpɔːʃn n. 部分，一份
预算的很大一部分用于教育，政府承诺维持这一比例。
现在完成时主谓 + 介词短语 + which 从句（现在完成 + promise to do）短语 a large portion of短语 portion out
A large ___ of the budget goes to education, which the government has promised to keep.
