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e. At one poin t, it seemed certain that their plane would crash. It could on ly get over the mountains if it ro se to 10, 000 feet. By rd at once ordered his men to throw out two heavy food sack s. The plane was then able to rise and it cleared the mountains by 400 feet. By rd now new that he wou ld be able to re ach the South Pole which was 30 0 miles away , for there were no more mountains
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為探索室內(nèi)人工飼養(yǎng)油桐尺蠖的最適環(huán)境條件,將油桐尺蠖幼蟲的養(yǎng)蟲籠置于溫度相對(duì)穩(wěn)定的25、27、29、31℃下,用新鮮桉樹葉在室內(nèi)飼養(yǎng),觀察整個(gè)幼蟲期的生長(zhǎng)狀況,統(tǒng)計(jì)其百蟲體重、成活率、化蛹率。結(jié)果顯示:在27~29℃的室內(nèi)環(huán)境溫度下,幼蟲取食活躍,3項(xiàng)統(tǒng)計(jì)指標(biāo)綜合評(píng)價(jià)最好,27~29℃可認(rèn)定為室內(nèi)桉葉飼養(yǎng)油桐尺蠖幼蟲的最適溫度。