你应该准备好随时接受新挑战,否则你会落后的。
You should ___________________, ___________________.
他对周围正在发生的事情充满好奇，总是问许多问题。
He ___________________ many questions.
The ________ (关系) between humans and nature is of great importance.
The picture on the wall often ________ (提醒) me of the time in the countryside.
John is never ________ (缺席) from class, no matter how far he lives.
Doctor Smith always works to high ________ (标准), and he wins high praise from others.
