①离子键没有方向性和饱和性,而共价键有方向性和饱和性
②配位键在形成时,是由成键双方各提供一个电子形成共用电子对
③金属键的实质是金属中的“自由电子”与金属阳离子形成的一种强烈的相互作用
④在冰晶体中,既有极性键、非极性键,又有氢键
⑤化合物NH4Cl和CuSO4•5H2O都存在配位键
⑥NaCl、HF、CH3CH2OH、SO2都易溶于水,但原因不完全相同.
A:①③
B:②④
C:②⑤
D:④⑥
行为的发生是受到神经系统和激素的调节作用。( )
与北京市相邻的省级行政区有( )
This Sunday is grandpa's birthday. The Smith family are going to celebrate it at home, so they will have a busy weekend.
Saturday
Morning
Dad-clean the car in the garden
Mum-clean the kitchen and bedrooms of their house
Amy-have dance lessons in the gym
Rose--work on science projects in the library
Afternoon
Mum and Dad-buy some food at the supermarket
Amy and Rose-choose gifts and cards for grandpa
Evening
Watch TV together
Sunday
Mum---make a big birthday cake
Amy and Rose-wrap grandpa's gifts
Amy-help Mum cook delicious food
Rose-help Dad decorate the sitting room
Amy and Rose-give gifts to grandpa
The whole family-have a party
根据表格所提供信息,从每小题所给的A、B、C三个选项中,选出一个最佳答案。