question: forward:backward
choices.label: A B C D
choices.text: spur:exhort sea:land vibration:quietness extend:compress
explanation: "forward" means the opposite of "backward". There is no obvious logical relationship between "to spur" and "to exhort". the earth consists of the "sea", the "land" and so on. The opposite of "vibration" is "stillness" not "quietness". The opposite of "compress" is "extend".
relation: forward backward R1.2
relation: sea land R2.4
relation: extend compress R1.2