—______ does it take Mary to go to the bubby club? —Twenty minutes.

—Remember to turn off the lights before leaving the classroom, children.—______.

David,an ＿＿boy can write in Chinese.

----Could you get home at five o’clock? ---- ________I’ll have a meeting at that time .

当你称呼李老师（男）时，应如何称呼？________.