为方便楼主看,我把楼主的几个短文编号：
一,I (buy)____a small git before i (go)_____to the hospital yesterday to visit my friend.
二,Yersterday afternoon I (go)_____to visit the Smith family.【 When i (get)_____there around two o'clock】,Mrs.Smith(be)______in the yard.She(plant)_______flowers in her garden.Mr.Smith (be)______in the garage.He (work)______on their car.He (change)________the oin.The children(play)_______in the front yard.In other wors,【 while Mr.Smith(change)_______the oil in the car】,the children (play)______with a ball in the yard.
三,I (hit)______my thumb 【while i (use)______the hammer】.Ouch!That(hurt)______.
四,【As soon as we (hear)______the news of the approaching hurricane】,we (begin)______our preparations for the storm.
五,It was a long walk home.Mr.Chu(walk)______until he (get)____tired.Then he (stop)_______and (rest)______until he (be)_____-strong enough to continue.
六,【While i (lie)______in bed last night】,i (hear)______a stange noise.【When i (hear)_______this stange noise,】 I (turn)_____on the light.I (hold)_____my breath and (listen)______carefully.A mouse(chew)_____on something under the floor.
七,I work at a computer all day long.Yesterday 【while I (look)______at y computer screeen】,I(start)______to feel a little dizzy,sorest of the day in ts I (take)_______a break.【While i (take)______a short break outdoors and (enjoy)_____the warmth of th sun on my face】,an elderly gentleman (come)_______up to me and (as)_____me for directions to the public library.【Ater i (tell)______him how to get there】,he (thank)__________me and (go)_____on his way.I (stay)_____outside until a big cloud (come)__________and (cover)_______the sun,and then i reluctantly (go)______back inside to work.【As soon as I (return)______to my desk】,I (notice)______that my computer(make)_______a funny noise.It (hum)_______loudly,and my screen was frozen.I (think)_____for a moment,then i (shut)________my computer off,(get)_______up from my desk,and (leave)_______.I (spend)______the rest of the day in the sunshine.
一,bought,went
二,went,got,was,was planting,was,was working,was changing,were playing,was changing,were playing
三,hit,was using,hurt.
四,heard,began.
五,walked,got,stopped,rested,was
六,was lying,heard,heard,turned,held,listened,was chewing
七,was looking,started,took,was taking,enjoying,came,asked,had told,thanked.,went,stayed,came,covered,went,returned,noticed,was making,hummed/.thought,shut,got,left,spent
【 】内的句子都是时间状语从句.
（很抱歉现在才看到你的问题,希望仍能帮到你.）