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【简答题】
胰凝乳蛋白酶的活性中心主要含有Ser195、 His57 、 His57 ; Asp102 和 Ser195 基,三者构成一个氢键体系,使其中的氧原子上的电荷转接成为强烈的亲核基团,此系统称为 电荷转接 系统或 。 .
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【简答题】完形填空。 Ben is ① some plans ② his summer holiday. ③ July, he wants to finish his homework and he would like ④ some housework at home. Sometimes, he ⑤ for his parents. In August, he ⑥ the Internet and p...
【简答题】Mrs. Chang, a new teacher at Park School, wants to know her students in Class 5, Grade 3. Here are the introductions of some of the students. Names Introductions Kelly Kelly has to go to cram school f...
【单选题】关于信息的说法哪种最准确完整的说法是( )。
A.
信息就是新闻消息。
B.
信息的概念非常广泛，从不同的角度对信息可下不同的定义。
C.
信息(Information)，广义地讲，它是信号的模拟型或其符号的集合。
D.
信息只指一般的行情消息。
【简答题】听对话，选择正确答案。 1. Where did Tom go when Jeff called? A. To the hospital B. To the school C. To the post office 2. Who has a cold? A. Tom B. Tom's father C. Tom's mother 3. Why does Jeff call Tom? A. He w...
【简答题】根据句意,用 and , but , or 填空。 prefix="o" ns="urn:schemas-microsoft-com:office:office" ?xml:namespace> 1. The
history test was difficult ________ the English test was easy. 2. My
name is Jim ________ I’m y...
【简答题】阅读对话，判断下列句子正“T”误“F”。 Tom: Mum, I want to go on a trip to Shijiazhuang. Can we go by plane? Mum: No, Tom. It costs too much. Let's take a bus. Tom: No, Mum, a bus is too slow. Mum: Okay. Let's take a t...
【简答题】阅读理解。 读短文，判断正（T）误（F）。 One day, Tom and his father go out for a walk. Suddenly they see a big brown dog. The dog begins to bark(汪汪叫). Tom is afraid. He wants to run home. His father says: “Don’t be afr...
【单选题】听力原文： Our family is trying to decide where to go for a vacation this summer. Our son Tom wants to go to Yellow Stone Park again to see the bears. We did that last summer and what an experience it was!...
A.
They haven't reached a decision yet.
B.
They have decided to go hunting bears.
C.
They want to go camping.
D.
They want to go exploring the country.
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