They can buy the pens _____ a very good _____.
John’s parents live______ him _______Shanghai.
It’s very hot these days. The temperature stays _____ 32℃.
Tom often helps me ______my math after school.
------How do you usually deal with the problems? ------I usually do that _______ thinking hard or asking the teacher for help.
-- Sally, you must introduce your friend ___________ me. -- OK, I will.