短周期主族元索X、Y、Z、W、R原子序数依次增大，X原子最外层电子数是其内层电子数的2倍，Y、R同主族，且两者核外电子数之和是x核外电子数的4倍，Z是迄今发现的非金属性最强的元素，在周期表中W位于ⅠA族。

请按要求回答：

核酸包括两类，一类是____ ，简称DNA，一类是____ ，简称为____ ．

下列各组物理量中，全部是矢量的有  (      )

下列地质作用中，属于内力作用表现形式的是（  ）

阅读下列短文，从每小题的三个选项中选出最佳选项。B
    Water comes from the sea, the rain and the tap. Animals, plants and human beings all need water. It is important for our daily (日常的）life. We use water to wash clothes and vegetables. We use water to cook food, make drinks, wash our face and so on. Firemen use water to put out fires. Fanners use water to grow crops. Water is useful. We mustn't waste (浪费）water. We must save water. Turn off the tap when you are brushing your teeth. Don't take a shower too long. Use the same water many times.