转基因食品比传统食品更优越、营养、有品质。对人类更有利。()
参考答案:错
解析:
转基因食品对人体的影响尚无定论。
--- ___________ is it from Suzhou to Beijing?
--- It used to be a long way, but nowadays, it takes only five hours to get there by high-speed rail.
A.How soon
B.How much
C.How far
D.How long
除去括号内杂质所用试剂和方法都正确的是 ( )
A.Cu(Fe)----加稀硫酸,蒸馏;
B.CO2(SO2)----氢氧化钠溶液,洗气。
C.NaCl溶液(碘)----酒精,萃取、分液;
D.KNO3溶液(KCl)----降温结晶,过滤;