未知题型 The author closely follows the basic 5-paragraph structure of the English essay. The essay is composed of 1) an introduction, 2) 2~ 4 body paragraphs, and 3) a conclusion. The introductory paragraph should end with a thesis statement that clearly presents the topic of the essay. Your body paragraphs should explore, explain and clarify the thesis through a focused, detailed, and purposeful exposition and/or argumentation. A standard paragraph is supposed to develop from a subtopic and last for 150~250 words.

问答题 怎么区分硬质、半硬质、软质泡沫塑料？

单项选择题 分子力场函数由以下几个部分构成