过抛物线y2=4x的焦点F作直线交抛物线于A（x1，y1），B（x2，y2），则x1x2=（ ）．
1
-__________
-By bus.[ ]
A. Why does he go to work?
B. How does he go to work?
C. When does she go to work?
D. Where does he work?
创伤急救“五项技术”是指（）.
A.通气、止血、包扎、固定、搬运
B.通气、止血、包扎、固定、清创
C.复苏、输液、止血、包扎、固定
D.输液、通气、止血、包扎、后送
E.通气、止血、包扎、固定、复苏
