The two strands in the DNA double helix are anti-parallel. What does this mean（）
A. Both strands run in the 3′ to 5′ direction
Both strands run in the 5′ to 3′ direction
C. Anti-parallel is used to refer to the left-handed curve of the DNA double helix
D. One strand runs in the 5′ to 3′ direction and the other runs 3 to 5 direction
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In the laboratory, DNA molecules can be cut at specific sequences using（）
A. UV light
B. restriction nucleases
C. DNA ligase
D. laser tweezers
E. DNA polymerase
Which of the following may NOT be used in argumentative essays to convince readers（）
A. Statistics
B. Personal beliefs
C. Personal experiences
D. Logical reasoning
Choose the best topic sentence for the following paragraph.______. For example, a person can have breakfast in New York, board an airplane, and have dinner in Paris. A businesswoman in London can inst
A. Technology has made people’s life more convenient
B. Advances in technology have made the world smaller
C. Technology has enriched people’s life
D. /
Tick （√）the correct inforamtion about topic sentences. A topic sentence is（）
A. at or near the start of the paragraph
B. at the end of the paragraph
C. the main idea of the paragraph
D. the main idea of the whole essay
E. made up of fatual details
F. made up of a topic and the writer’s assertion
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