15.D。the number of表示“……的数目”,而a number of表示“许多……”。
100
Mr.
Robinson had to travel somewhere on business, and as he was in a hurry, he
decided to go by __1__ . He liked sitting __2__ a window when he
was flying, so he got onto the plane, he looked for a window seat. He __3__
all of them taken except one. There was a young man __4__ beside it, and
Robinson was surprised that he had not taken the one by the window. Anyhow, he
went towards it.
When
he __5__ it, however, he saw that there was a notice on it, written __6__
large letters, __7__ “This seat is kept for proper balance. Thank you.”
Mr. Robinson had never seen such a notice before, but he thought the plane must
be carrying something particularly heavy in its room __8__ made it
necessary to have the passengers properly balance. So he walked on and found __9__
empty seat, not beside the window __10__ .
Two
or three other people __11__ to sit in the window seat next to the young
man, but they also read the notice and went on. Then when the plane was nearly 12__ a very beautiful girl __13__
into the plane. The young man, who was watching the passengers coming in, 14__ took the notice __15__
the seat beside him, and by this means succeeded in having a pretty companion
during the whole trip.