【正文】 考查代詞用法。只有what 可用作賓語并且指事物。 句意：生命是如何在地 球上開始的是科學家們覺得難以破解的謎團之一。 當名詞性從句在句中作主語時，為避免句子頭重腳輕，常用 it 作形式主語置于句首，而將真正的主語 從句放在句尾。第一個空 what“??的”引導主語從句，且在從句中作主語；第二個空連詞 that 引導表語從句， that 在 從句中無意 義，不作成分。江蘇高考 ) It was never clear the man hadn’t reported the accident sooner. A. that B. how C. when D. why 21. (2021 that 2. (2021 it 4. Cindy shut the door heavily and burst into tears. No one in the office knew she was so angry. A. where B. whether C. that D. why 5. (2021山東高考 ) The two girls are so alike that strangers find difficult to tell one from the other. A. it B. them C. her D. that II. 將下列句子改為含有名詞 性從句的復合句 1. The population of China is the largest in the world. It is known to all. the population of China is than of any other country in the world. 2. “How long will it be before we go to Jiuzhaigou?” the little boy asked. The little boy asked . 3. — When will they leave for New York? — It hasn’t been decided. → . 4. — Is your hometown a small village? — No. But it used to be. My hometown is no longer . 5. Will ways be found to stop the pollution? The public are worried about it. → / / . III. 完成句子 。分析句子結構可知，第一個空 as 引導時間狀語從句；第二個空 that 引導同位語從句，解析說明 feeling的內容。 根據從句中缺少的句子成分是狀語，排除D 項，而答案 B、 C 均與題意不符，所以 應選 A項。 I’m afraid 后接一個賓語從句； which 引導一個非限制性定語從句，對“ he’s more of a talker than a doer”進行補充說明，而這一點，正是“他一事無成的原因”。