a warship that can operate both on and under water

tàu ngầm, tàu lặn
a type of small vehicle that is used to travel on water

thuyền, tàu
beneath the surface of a body of water

dưới nước, ngầm
to visit places one has never seen before

khám phá, thám hiểm
the great mass of salt water that covers most of the earth's surface

đại dương, biển
the armed forces of a country

quân đội, lực lượng vũ trang
a flat part of a bicycle or machine that is pushed with the foot to make it move or operate. It is typically circular and part of the mechanism that drives motion

bàn đạp, pê đan
a machine that uses steam made from boiling water to produce power and make parts move

động cơ hơi nước, máy hơi nước
a state of armed fighting between two or more groups, nations, or states

chiến tranh
the war that took place from the year 1914 to 1918 between the allies and the central powers

Thế chiến thứ nhất
the war that took place from the year 1939 to 1945 between the axis and the allies

Chiến tranh Thế giới thứ hai, Thế chiến II
to act violently against someone or something to try to harm them

tấn công, tấn công
a country or its forces that one is fighting against in a war

kẻ thù, đối thủ
an internal-combustion engine that burns heavy oil

động cơ diesel, động cơ chạy dầu
a device that produces electricity; may have several primary or secondary cells arranged in parallel or series

pin điện, ắc quy điện
newly developed and incorporating new, modern methods or technology

tiên tiến, đổi mới
a type of energy generated by splitting atoms to release their stored energy

năng lượng hạt nhân, công suất hạt nhân
to prevent someone or something from being damaged or harmed

bảo vệ, che chở
someone whose job or education is about science

nhà khoa học, nhà nghiên cứu
the earth's surface where it is not under water

đất, mặt đất
to keep something in a particular place for later use, typically in a systematic or organized manner

cất giữ, lưu trữ
