【推荐1】These inventions have brought us happiness and are performing _________important function in our life. We shouldn’t ignore their disadvantages. (用适当的词填空)

【推荐2】Like many undergraduate biology students, Wang Fang was taught that pandas are a prime example of ________ umbrella species — a well-known and usually endangered animal.(用适当的词填空)

【推荐3】Children have ________urge to meet the astronauts coming back from the ShenzhouXII spacecraft. （用适当的词填空）

【推荐2】Saxaul trees are __________ excellent tree species for sand fixation. It’s commonly seen, though easily ignored. (用适当的词填空)