骨有两种类型, 即松质骨与坚质骨. The ice is hard enough to skate on. 冰层已够坚厚,可以滑冰. The workers were tunnelling through solid rock. 工人们正在坚石中挖掘一条通道. Xiangzi was indeed rather like a tree, sturdy , silent yet full of life. 他确乎有点像一棵树, 坚壮, 沉默,而又有生气. The woman folded her child to her bosom, and walked firmly and swiftly out. 那妇人把孩子紧紧搂在怀里, 坚定地,匆匆地向外走去.