“下午好,孩子们。”可以这样说:________A.Good afternoon,boys and girls. B.Good night,boys and girls.
( ) Even the top students in our class can’t work out this problem. So it _____ be very difficult.
() This machine is very easy to use.______ can learn to use it in a very short time.
( ) One of his friends ______ his daughter sometimes.
( ) The game is _____ funny that many of them like it.
( ) Are there _____ trees behind the house?