Vocabulary consisting only from characters you are able to read
二人
futari
two persons, two people, pair, couplejlpt5
土木
doboku
public worksmix
山
yama
mountain, pile, heap, climax, critical pointjlpt5, shizen
山川
sansen; yamakawa; yamagawa
mountains and rivers; mountains and rivers; mountain riversmix
水力
suiryoku
hydraulic power, water powermix