罐头食品主要有哪些腐败变质现象？
参考答案：
胀罐、平盖酸坏、黑变和发霉等腐败变质现象，此外还有中毒事故。
1950年6月，中 * * 党为争取国家财政经济状况的基本好转而召开的重要会议是（ ）
A．中共七届二中全会
B．中共七届三中全会
C．中共七届四中全会
D．中共七届五中全会
Why have the Americans developed space shuttle according to the passage
Which of the following statements is NOT true according to the passage
A．The term "averted vision" refers to the act of looking out of the comers of one’s eyes.B．If you want to see very faint things, you should better look sideways rather than straight on.C．The receptors located in the eye’s center are less sensitive to dim light.D．To "look" is to see something straight ahead.
