—Yes, at _______ it's _______ the one you bought for me.
A:last; as bad as
B:least; no better than
C:last; not better
D:least; no worse than
现代科学又发现了H3、C60、C90、C240、N5、N60…据此可做出的推测是( )
①同一种元素可以形成多种单质;
②单质可能存在复杂的分子结构;
③单质的研究具有广阔的前景;
④同种元素形成的单质之间可能存在更多的相互转化.
选出下列各句中加线成语使用恰当的一项( )
如图,在△ABC中,∠C=90°,AD平分∠CAB,已知CD=3,BD=5,则下列结论中错误的是( )
The road is so narrow that buses are unable to .