Nor can we discount the possibility that some factor in the diet itself has harmful effects.
ADJ-GRADED 悲观的Someone who is pessimistic thinks that bad things are going to happen.
Not everyone is so pessimistic about the future...
不是每个人都对未来如此悲观。
ADJ 破产的；倒闭的；资不抵债的People or organizations that go bankrupt do not have enough money to pay their debts.
If the firm cannot sell its products, it will go bankrupt...
如果公司的产品卖不出去，它就会倒闭。