题目

关于加速度的概念，下列说法中正确的是(        ) A、加速度表示物体运动的快慢 B、加速度表示物体速度变化的大小 C、加速度的方向一定与物体运动方向相同 D、加速度表示物体速度变化的快慢 答案：D1．每句有一处错误，请按以下要求改错：错误：把某词改为某词．写为：某词---某词．例如：was--were增加：在某词后加某词．写为：某词后加某词．例如：by后加the删除：去掉多余的词．写为：去掉某词．例如：去掉a71．Comparing with 2005，the price of grain was increased by 50%．72．Rather than driving himself，he always prefers to ride a bicycle．73．It will depend on if this problem can be solved．74．I have some doubt that they can complete the task on time．75．This teacher often helped me maybe because he felt itself his duty to do so．76．Some of the tall trees were measured over 90 metres．77．It's very late to take any buses，so we have to walk home．78．As long as I know，they live in the same neighbourhood．79．The organization is in charge of David who is very capable of managing it．80．We took turn to drive when going to the seaside．