疾病自然史是疾病从发生到结局(死亡或痊愈等)的全过程，包括：()、()、临床期和结局四个阶段。
What is the passage mainly about？
A. Hard economic times in France.
B. People"s Christmas wish.
Changes of people"s attitude towards gift-giving.
D. Eco-friendly products.
GB/T9695.7-2008规定，肉蛋制品脂肪含量测定中所用的提取剂不应含有()，它的存在会导致脂肪氧化，在反应时可能有爆炸的危险。
A. 过氧化物
B. 碱类
C. 浓酸
D. 水分
What is the news mainly about？
A. Causes of early death in Russia.
Behavior. of alcoholics.
Causes of alcohol poisoning.
D. Number of death over 10 years.
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