Bear went on to spend three years as a soldier in the British Special Forces. It was there (a)   he perfected many of the skills in wrestling with Mother Nature. (填入适当的连接词)

In 2008, fewer than 100,000 self-service checkouts were in operation worldwide. Tesco(乐购) was the first major supermarket (a)   (introduce) them, aiming to make the customer checkout experience more efficient.

The very fact (a)   there is a need for self-service “assistants” in some supermarkets shows the fundamental flaw (瑕疵; 弊端) of these machines. (填入适当的连接词)

The little boy doesn’t mind (a)   alone at home. (leave)

(a)   reasons of security, all schools outings were cancelled until an investigation was held to see if the safety of students could be improved. (填入适当的介词)

Officials tend to be timid creatures and prefer to err on the side of caution, even if that means (a)   (deprive) students of valuable learning experiences such as school outing.

These trips can be safe _____ _____ _____ you are properly prepared, such as wearing appropriate clothing and shoes. (填入适当的连接词，一空一词)

(a)  

Now, you (a)   (surround) by cool-looking stuff and…you’re in danger of going over your monthly budget.

(a)   (try) to figure out the value of the price tag (标签) on our head can be difficult.

Sometimes a person's value (a)   (base) upon reputation.

Thinking about our worth in the job marketplace can enable us (a)   (discover) new career paths.

Shanghai is known as the (a)   center of China. (finance)

That hotel is famous for its special medical care that can help the (a)   . (able)

It’s important for students to build relationships with other members of the (a)   . (social)

Alice bought a large carton of ice cream. She ate some and (a)   the rest. (freeze)

The (a)   of the children made their parents very worried. (appear)

In the educational program four players will (a)   with animals for food. (competition)