There may be no training classes on a camp day if_____.

(单选题)What does the underlined word in Paragraph 3 mean? (单选题)What does the new study show? (单选题)What can we know about the red spruce trees? (单选题)Why does the author mention West Virginia in Paragraph 3? (单选题)What’s the advantage of forests compared with the existing e (单选题)（ ） (单选题)According to the passage, you should not swim alone because (单选题)The stoke that some young swimmers use first is ______ (单选题)The author believes that fear of water is ______. (单选题)Little children can learn to swim as soon as soon as ______.