sphere

n.球体；(活动)范围，(研究)领域

spellbinding, spellbound, speller, spelling, spelt, spelunker, spend, spend...time (in) doing, spender, spending, spendthrift, spent, sperm, sperm whale, spermaceti, spermatozoon, spermicidal, spermicide, spew, sphagnum, spherical, spherically, spheroid, sphincter, sphinx, spice, spiced, spiciness, spick, spicy, spider, spider plant, spider-man, spidery, spied, spiel, spigot, spike, spikiness, spiky,