实验材料:培养液、疟原虫甲、疟原虫乙、3H-异亮氨酸、1.0×10-6mol/L 青蒿素溶液、
DMSO(用于配制青蒿素的溶液)、放射性测量仪。
对于任意实数,代数式x2-4x+5的值是一个( )
① The book is mine. ____ A. It's Mike's book.
② The book is Amy's. ____ B. The book is theirs.
③ It's their book. ____ C. Its' Amy's book.
④ The book is Mike's. ____ D. It's my book.
根据板块构造学说,几千万年以后可能消失的海洋是( )
无水酒精(含乙醇99.5%以上)的制法通常蒸馏不能制得纯酒精,浓度为94%~96%时,即为恒沸溶液.工业酒精(96%)→无水酒精(99.5%)的方法 ____