材料一：予性好高，好高则倨傲而不能下。然所不能下者，不能下彼一等倚势仗富之人耳。否则稍有片长寸善，虽隶卒人奴，无不拜也。予性好洁，好洁则狷隘不能容。然所不能容者，不能容彼一等趋势谄富之人耳。

材料二：以为天下利害之权皆出于我，我以天下之利尽归于己，以天下之害尽归于人，……然则为天下之大害者，君而已矣。向使无君，人各得自私也，人各得自利也。呜呼，豈设君之道固如是乎！

请回答：

一个物体做匀速直线运动，在10s内通过20m，它在前2s的速度是         （   ） 

用“who”或“that”填空
(1) The man____  is talking with my mother is my father .
(2) That book is the one____  I bought yesterday .
(3) He is one of the workers ____  been saved in that accident .
(4) They talked of the things and persons ____  they remembered in the factory .
(5) All____  can be done must be done .