固体A的化学式为NH5,它的所有原子的最外层都符合相应稀有气体原子的最外电子层结构,则下列是有说法中,不正确的是( )
A.1molNH5中含有5NA个N—H键(NA表示阿伏加德罗常数) |
B.NH5中既有共价键又有离子键![]() |
C.NH5的电子式为:[H:N:H]+[:H]- H |
D.它与水的反应的离子方程式为:NH4++H-+H2O=NH3·H2O+H2↑ |
All the dishes in this menu, ______ otherwise stated, will serve two to three people.
A.as | B.if | C.though | D.unless |
The children loved their day trip, and they enjoyed the horse ride ______.
A.most | B.more | C.less | D.little |
Progress______ so far very good and we are sure that the work will be finished on time.
A.was | B.had been | C.has been | D.will be |
Charles was alone at home, with_______ looking after him.
A.someone | B.anyone | C.not one | D.no one |
It is often ______ that human beings are naturally equipped to speak.
A.said | B.to say | C.saying | D.being said |