质点做直线运动的位移x与时间t的关系为x=5t+t²（各物理量均采用国际制单位），则该质点（   ）

已知：|a|=3，$\sqrt{b^2}$=5，且|a+b|=a+b，则a﹣b的值为（　　）

根据句意，用括号内单词的适当形式填空
（1）Stop ____  (make) so much noise. My father is sleeping .
（2） When I have an exam, I feel____  (worry) .
（3） Cathy ____ (go) to school on her bike yesterday.
（4）Bicycle is another way of____ (say) bike.
（5）You needn't____  (finish) your homework today. You can di it tomorrow.
（6） Do you know where Mike____  (live) ?
（7） A number of students in our school ____ (be) from the countryside.
（8） I take a taxi to work when it____  (rain).
（9） There are a few____  (different) between the two pictures.
（10） They often go bike____  (ride) on weekends .