题目

西部牧业灾害具有更大的风险和更重的灾情是因为西部地区 ①草原面积广阔，经济落后 ②经营粗放，靠天养畜 ③自然灾害种类多样④农业受灾体脆弱 A.①②     B.②③    C.③④    D.②④ 答案：AIt was only when I reread his poems recently__________ I began to appreciate their beauty.A．untilB．in whichC．thatD．so