【单选题】What can't a good hearty laugh help do?
【多选题】关于氢键说法正确的有( )
A.
氢键力是一种由氢原子引起的特殊的分子间相互作用力
B.
氢键本质上与范德华键一样,是依靠分子间的偶极吸引力结合在一起
D.
具有-OH 、-COOH 、-NH2 等侧基基团的线性高分子材料均存在明显的氢键力
【判断题】Solid filter refers the filter that does not require tuning.
【单选题】It was such a funny show that people couldn’t help__________ again and again.
【单选题】A laugh can help people over an (awkward) situation.
【单选题】The story was so funny that we
( ) A. couldn't help laugh B. can't but laugh C. couldn't help laughing D. couldn't help but to laugh
【多选题】关于氢键说法正确的是?
A.
氢键是一种由于氢原子结构特殊性所形成的特异键型
C.
在极性溶剂中,如果溶质分子能与溶剂分子形成氢键,则溶质的溶解度增大
D.
分子内形成氢键会使物质的熔沸点降低,分子间形成氢键,会使物质的熔沸点升高
【简答题】I can’t help _____ (laugh) at his joke.