8天堂资源在线,国产成人久久av免费高潮,国产精品亚洲综合色区韩国,国产欧美va天堂在线观看视频,xx色综合

請(qǐng)寫(xiě)出如圖18所示的幾個(gè)實(shí)驗(yàn)所揭示的物理道理：

甲：                                                                     

乙：                                                                     

丙：                                                                     

丁：                                                                     

請(qǐng)寫(xiě)出如圖18所示的幾個(gè)實(shí)驗(yàn)所揭示的物理道理：

甲：                                                                     
乙：                                                                     
丙：                                                                     
�。�                                                                     

請(qǐng)寫(xiě)出如圖18所示的幾個(gè)實(shí)驗(yàn)所揭示的物理道理：

甲：                                                                     

乙：                                                                      

丙：                                                                     

丁：