【简答题】读海报, 判断以下陈述的正误。 Ø ( ) 1) Salad sauce is on sale on 9th, Oct. Ø ( ) 2) There are three items on sale on 10th, Oct. Ø ( ) 3) Oil is cheaper on 5th, Oct. Ø ( ) 4) Cell phone is ¥ 1668 fro...
【单选题】_______means the level for which appropriate additional protective security measures shall be maintained for a period of time as a result of heightened risk of a security incident.