'Des tennis' are most probably 'des (chaussures de) tennis' which are tennis shoes in English. That could also stand for 'des (terrains de) tennis', which are tennis courts.
"des tennis" are the sport shoes called sneakers in English.
tennis courts
"des couteaux" means "knives" in English
'des visiteurs' means 'visitors' in English.
"des jumeaux" means 'twins' in English. (these are male twins; the feminine is 'des jumelles')
des chaussettes are 'socks' in French.
The English word for "Des Crayon" is "The Pencil".
markers
scissors
boots
"Eau des merveilles" would be translated "water from the marvels" in English.
"roi des ... (+ a plural noun)" means "king of ..." in French.