阅读理解：

　　My grandfather was a teacher. He was the head teacher of a school for boys between the ages of thirteen and eighteen. I know that he was a kind and gentleman at heart, because when I was young (and he was old), he gave me presents, and sat me on his knee, and told me stories. But I believe the boys at his school were afraid of him.

　　At school, when he walked into a room full of noisy boys, there was silence(平静) at once. When he looked at a boy with a certain look in his eye, that boy went red in face, and looked down at his shoes. If a boy brought him poor, careless work, work that was not the best that boy could do, my grandfather picked up the boy's book and threw it across the room, shouting:“Do it all again, and bring it back first thing in the morning!”If the boy was late, or if he forgot to bring the work, he had to do it again, and again, and yet again. My grandfather never forgot.

　　He was a very different man at school, from the man I saw day by day in his own home.

1．My grandfather was kind and gentle, because ________.

[　　]

A．he was the head teacher of a boys' school

B．he gave me presents and told me stories

C．he told me stories about how kind he was

D．he let me sit on his knee and tell him stories

2．When he looked at a boy in a certain way, that boy ________.

[　　]

A．went red in the face and could not return my grandfather's look

B．looked back at my grandfather's red face

C．looked at his shoes to see if they were dirty

D．went red in the face because his shoes were dirty

3．My grandfather did not like to receive ________.

[　　]

A．worse work than he could do himself

B．work that the boys could not do

C．work that was not as good as the boys could do

D．the most careful work that the boys could do

4．When he received poor work, my grandfather ________.

[　　]

A．shouted at the boy and threw his work across the room

B．went red in the face

C．threw the book on the floor, and shouted across the room

D．threw the book at the boy