分解因式：m2﹣4=____．
For our safety, we'd better avoid ____ (go) out alone at night.
如图，平面四边形ABCD中，AB= 5 ，AD=2 2 ，CD= 3 ，∠CBD=30°，∠BCD=120°．
2013年3月，******首次出访的国家中，既跨两大洲又跨东西半球的是（ ）
- Who gets up ______ in your family?
- My mother. She has to cook breakfast for my father and me.
