Choose the word or phrase among A, B, C or D that best fits the blank space in the following passage.

During the war, children wore straw hats to (16)_________ themselves from debris. Houses and schools were bombed and destroyed. Many children were made (17)_________ and their schools had to be moved around or lessons sometimes had to (18)_________ after dark to avoid being targeted by heavy bombing. Many schools had its roof (19)_________ with several layers of straw to withstand the (20)_________ of the bombs. Life for children was very hard in both the North and South of Viet Nam during the war.

Young people were (21)_________ of their duty to serve their country. Even young girls took part in the war efforts by digging bomb shelters. Children took first-aid courses after school so that they could (22)_________ injured people.

Childhood years of children born in the 1960s are (23)_________ . As innocent children, they went to school (24) _________ straw hats in the sounds of American jet fighters in the sky and the shots from Vietnamese anti-aircraft guns.

Nowadays, they are proud that they came through those hardships. They had their heads held (25)_________ walking out of the war.