When you read the book, you' d better make a mark _____ you have any questions.
. ---I usually go there by train. ---Why not _______ by boat for a change.
.He pretended _______ nothing about it.
. Little Jim should love _______ to the theatre this evening.
. They would not allow him _______ across the enemy line.
. There are so many kinds of tape-recorders on sale that I can’t make up my mind ____to buy.