【单选题】The fact is _____I earned my passage by working as an unpaid hand, _______accounts for my appearance.
【单选题】There are ____ left unpaid.
C.
two item of commissions
D.
two items of commission
【单选题】The word 'debts' in 'very few debts are left unpaid' in the first paragraph means_____.
【简答题】生物多样性,简单地说,就是生物及其 的多样性;确切地说,生物多样性包括 、 和微生物及其所拥有的全部 和各种各样的 。