【简答题】More and more carbon dioxide from burning the coal and oil is (5) ________ into the air every year. The carbon dioxide can absorb the heat from the earth. The more carbon dioxide in the air, the more ...
【单选题】关于苯骈二氮杂卓类药物的鉴别反应的现象,以下说法不正确的是
A.
加硫酸后呈现不同的颜色,且一般在浓硫酸中的颜色与在稀硫酸中的颜色也不同
C.
1位N未被取代的苯骈二氮杂卓类药物水解后可以发生芳伯胺基反应
【单选题】The heat from the sun can't escape because of too much ______. [ ]
【单选题】The trees can part of the heat from the sun.
【简答题】将下列段落翻译成中文 Geothermal heat pumps, which use the earth as a heat sink in the summer and a heat source in the winter are viable nationwide.Therefore,they rely on the relative warmth of the earth for the...
【判断题】人口因素在社会发展中的作用是可以制约和影响社会发展。