单项选择题
ROE: FISH ::（）
A．skin: whale B．shell: mollusk C．pincer: crab D．egg: bird E．web: seal
单项选择题 VERIFY: DOUBTFUL ::（）
单项选择题 SOUND: ECHO ::（）
单项选择题 Though （） in his youth, Muir grew in the fullness of time to acquire truly （）habits envied by even the most hardened of his fellow survivalists.
