---Why didn’t the little boy raise his hand in class today ?---- Maybe the questions are ______ difficult for him_______ answer .
These books and magazines are useful.Don’t________
Guilin is a beautiful city and it is known________its mountains and lakes.
She wants to visit a place________people are friendly.
In the city,many old buildings will be________next year.
—In a text message,88 means Bye-bye. —And another example is F2F_______stands for face to face.