单选题 There are _____ reasons why people like traveling.

单选题 Regular exercise can _____ your physical strength.

单选题 The ancient _____ of Egypt is famous for its pyramids.

单选题 The company decided to _____ more staff to handle the big project.

单选题 The new technology aims to _____ all previous achievements in this field.

单选题 Due to the economic crisis, the company's profits have started to _____ this year.

单选题 The school tries to _____ students from different backgrounds.

单选题 The worker used a _____ to make a hole in the metal plate.

单选题 The invasive species _____ the local ecosystem.