下列哪种药物是繁殖期杀菌药（） A.青霉素 B.四环素 C.链霉素 D.氯霉素 E.

Here are reports of three attacks. The three swimmers were attacked by sharks because they didn’t obey (遵守) the safety rules for swimmers.

Rules for swimmers: A. Don’t swim at night. B. You are more likely to be attacked in warm water. C. Sharks are attacking by blood. Don’t swim with an open cut. D. It’s best to wear a swimming suit to match your skin colour. Sharks can see colours. E. If you see a shark,don’t be nervous. Try to! swim quietly, with even (平稳的) strokes(划水动作).

Which rule didn’t each of the following swimmers obey?
小题1: Report 1: Colin was swimming with two friends
very late at night. He was attacked by a shark and died.
小题2:Report 2: Ann was a very good swimmer. She
bought a new bright red swimming suit. She was swimming with some friends when a shark attacked her.
小题3:Report 3: Jack was on holiday in Australia. He
cut his foot on the beach. He went swimming the same day and got at­tacked.