Thank you for the trouble that you had ________me with my studies.
China’s growth is not _____ threat to others. On _____ contrary, it will bring more opportunities to the world.
John is the tallest boy in the class, _______ according to himself.
What the science teacher does and says ____ of great importance to college students.
The year 2007 ______ remarkable changes in Changzhou’s landscape.
The children were catching butterflies in the garden. Some caught a lot, and others caught _______ at all.