9.（ ）

(单选题)Air pollution is becoming worse. As is known to all, air to (单选题)The office staff ______ gathered to hear the manager speak a (单选题)______, glasses can correct most sight defects, whether near (单选题)We have been told that under no circumstances ______ the tel (单选题)To my surprise, the majority of the students ______ in favor (单选题)To ______ their new shampoo, they are selling it at half pri (单选题)For a successful business, friendly and ______ staff are ess (单选题)______ all our efforts to save the school, the authorities d (单选题)His parents ______ him the opportunity to go to university. (单选题)She’s an only child, but they didn’t really ______ her.