A、B、C、D、E五种短周期主族元素，它们的原子序数依次增大。已知：A和C、B和D分别位于同主族，且B、D质子数之和是A、C质子数之和的2倍。下列说法正确的是
A．原子半径的大小顺序：r（B)>r（C)>r（D)
B．C的最高价氧化物对应水化物的碱性在同周期中最强
C．E分别与A、C形成的化合物中化学键类型相同
D．B的简单气态氢化物的热稳定性比D的弱
( )It is ______in October andNovember.
A. hotB. warmC. cool
( )They have presents _____ everyone.
A. ofB. forC. to
( )______ is the twelfth and last month of the year.
A. OctoberB. NovemberC. December
( )There are ________days in January.
A. twenty-nineB. thirtyC. thirty-one
( )This is ___________.It is June first.
A. Children’s DayB. New Year’s DayC. Teachers’ Day