—Let's play computer games.
—That _________ good.
A：looks
B：watches
C：sounds
D：has
已知AB→=1,k,AC→=4,2,AB→≤5,k∈z,则△ABC是钝角三角形的概率为 （ ）
平面上4条直线相交，交点的个数是（ ）
用适当的化学符号和数字回答：
________Tom________ Mary speaks good Chinese, so they can talk with these Chinese students very well.
