通读下面的短文，掌握其大意。从每小题的四个选项中选出可填入相应空白处的最佳选择，并把它前面的大写字母填入左边括号里。

　　Mr. Jones woke early one morning， before the sun had risen. It was a beautiful morning， _31_ he went to the window and looked out. He was _32_ to see a neatly-dressed and mid-aged professor， who _33_ in the university just up the road from Mr. Jones‘ house， coming the direction of the town. He had grey hair thick glasses， and was _34 an umbrella， a morning newspaper and a bag. Mr. Jones thought that he must have _35_ by the night train _36_ taking a taxi.

　　Mr. Jones had a big tree in his garden， and the children had tied a long _37_ to one of the branches， so that they could swing on it.

　　Mr. Jones saw the professor _38_ when he saw the rope and looked carefully up and down the road. When he saw that there was _39_ in sight， he stepped into the garden (there was no fence)， put his umbrella， newspaper， bag and hat nearly on the grass and _40_ the rope. He pulled it _41_ to see whether it was strong enough to take his weight， then ran as fast as he could and swung into the _42_ on the end of the rope， his grey hair blowing all around _43_. _44_ he swung， sometimes taking a few more _45_ steps on the grass when the rope began to swing _46_ slowly for him.

　　_47_ the professor stopped， straightened his tie， combed his hair carefully， put on his hat， _48_ his umbrella， newspaper and bag， and continued _49_ his way to the university， looking as _50_ and correct and respectable as one would expect a professor to be.

　　( )31.A. because B. as C. so D. for

　　( )32.A. surprised B. glad C. worried D. excited

　　( )33.A. studied B. worked C. stayed D. lived

　　( )34.A. passing B. doing C. carrying D. sending

　　( )35.A. left B. gone C. taken D. arrived

　　( )36.A. because of B. instead of C. by D. with

　　( )37.A. rope B. line C. stick D. ruler

　　( )38.A. run B. walk C. jump D. stop

　　( )39.A. nothing B. nobody C. no room D. no house

　　( )40.A. carried B. grasped C. took D. threw

　　( )41.A. hard B. high C. heavily D. greatly

　　( )42.A. garden B. tree C. land D. air

　　( )43.A. hands B. his shoulders C. his face D. his neck

　　( )44.A. Backwards and forwards B. Up and down

　　C. Left and right D. Around and around

　　( )45.A. running B. stopping C. rising D. falling

　　( )46.A. enough B. more C. too D. less

　　( )47.A. At first B. At last C. At once D. At least

　　( )48.A. set up B. gave up C. send up D. picked up

　　( )49.A. on B. for C. by D. with

　　( )50.A. clean B. slow C. funny D. quiet