下圖是某興趣小組在探究綠色植物光合作用過程中的實驗設(shè)計:

請據(jù)圖分析回答:
(1)根據(jù)以上實驗設(shè)計分析,甲、乙是一組          實驗,實驗變量是             
(2)請比較甲、乙裝置中蠟燭燃燒時間的長短:                                  ,產(chǎn)生該結(jié)果的原因是                                      。
(3)以上實驗最好重復(fù)多次,目的是                            。
(4)實驗時,如果乙裝置用黑布罩住,與之前沒有用黑布罩住的相比較,蠟燭燃燒時間將            (選填“延長”、“不變”或“縮短”),原因是                       。
(5)根據(jù)以上的實驗探究,寫一條提高大棚農(nóng)作物產(chǎn)量的措施                      。
(1)對照 綠色植物
(2)乙比甲長 乙中綠色植物光合作用釋放氧氣
(3)避免實驗結(jié)果的偶然性(其他答案均可)
(4)縮短 沒有光照綠色植物不能進(jìn)行光合作用,無氧氣釋放
(5)延長光照時間(或 “增加二氧化碳濃度” “合理密植”等)解析:
光合作用會釋放出氧氣,供蠟燭的燃燒,為了使實驗有說服力,實驗中一定要設(shè)置對照組。在設(shè)計對照實驗時,要遵循單一變量的原則。實驗常常要重復(fù)多次,才能得到比較可靠的結(jié)果。黑布罩住。植物不能進(jìn)行光合作用,就不能釋放出氧氣。所以蠟燭會很快的熄滅。
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