I'd like to congratulate all the students which are here today．改正：
A B C
Mike hardly hung out last winter vacation，doesn't he？改正：
A B C
What was happened to him the day before yesterday？改正：
A B C
This is Gina's and Tina's bedroom．It's small but tidy．改正：
A B C
It's very hot today，please keep the windows opening．改正：
A B C