科学研究表明,室外锻炼最佳时间是什么时候?()
A.下午或傍晚
B.早晨、傍晚
C.早晨、晚上
参考答案:A
1H-NMR中母核质子有三组四重峰,J值分别为11.0Hz,5.0Hz,17.0Hz的化合物是( )
A.5,7,4’-羟基黄酮醇B.5,7,4’-羟基黄酮C.7,4’-羟基异黄酮D.5,7,4’-羟基二氢黄酮醇E.5,7,4’-羟基二氢黄酮
The wrong you have done him is terrible, ___ I think, you should make an apology to him.
A.which
B.what
C.that
D.for which