購入: purchase or buy

後背位: doggy style

難航: rough time, rough passage / 軟鋼: (metallurgy) mild steel / 軟膏: ointment / 南航: (nautical) southbound / 南郊: southern suburbs / 南行: southbound

難航: have a hard flight, have a rough passage; run into difficulties, have a rough time

高額: large amount of money / 工学: engineering / 光学: optics / 後学: future reference / 好学: love of learning

抗菌: antibacterial / 公金: public funds / 拘禁: detention, imprisonment / 咬筋: masseter muscle / 行金: bank money

勾配: slope, inclination, gradient / 購買: purchase, buying / 紅梅: a type of Japanese plum / 公売: public sale

甲殻類: crustacean

後見: guardianship / 貢献: contribution / 高見: watching with detachment / 高検: High Public Prosecutors' Office / 効験: effect / 公権: civil rights / 後件: consequent

貢献: contribute / 後見: have guardianship over, have wardship over