多数恶性肿瘤的发生机制都是在什么的基础上发生的
A. 微生物感染
B. 放射线照射
C. 化学物质中毒
D. 遗传物质改变
E. 大量吸烟
[音频]7.
A. Three groups of learners.
B. The importance of business English.
C. English for Specific Purposes.
D. Features of English for different purposes.
8.
A. They want to change the way English is taught.
B. They know clearly what they want to learn.
C. They want to have an up-to-date knowledge of English.
D. They learn English to find well-paid jobs.
9.
A. College students.
B. Professionals.
C. Beginners.
D. Intermediate learners.
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