A．relationshipsB．membersC．troublesD．incomeWe want to kn……

单项选择题All living organisms, regardless of their unique identity, have certain biological, chemical, and physical characteristics in common.

单项选择题Practically all species of animals communicate either through sounds or through a large repertory of soundless codes.

单项选择题She gave up her job to look after her invalid mother.

单项选择题I hope you have left none of your belongings in the hotel.

单项选择题I could recognize the old car at a glance.