单选题 Bees can ______ over 10 similar flower smells with their sharp sense of smell.

单选题 Reliable evidence must ______ back acceptable conclusions in lawsuits.

单选题 The guest speaker decided to ______ his speech to leave enough time for audience questions.

单选题 A set of ______ economic policies helped China realize stable recovery amid challenges.

单选题 Researchers studied the bad results caused by sleep ______.

单选题 Many freshmen meet trouble ______ to campus life after entering university.

单选题 The company held training courses for staff not ______ in social communication.

单选题 China's wind power capacity has ______ the previous level greatly.

单选题 Perseverance in hardship is the most valuable ______ in my whole life.