心绞痛发作的典型部位为（）

A.心前区

B.胸骨中、上段胸骨后

C.胸骨下段

D.心尖部

E.剑突下

You want to know what the safest place for children 77．______
is in the car The experts say the back seat is the safest for 78．______
them. The back seat is farthest away off the force of a head- 79．______
on collision(迎头撞击), which can lead serious injuries. 80．______
If your child is below 8 and weighs no more than 85 81．______
pounds, it is necessarily to fit your car with a safety seat. 82．______
Moreover, the safety seat must be held in place of on the83．______
car’s back seat. If your child do need your attention while 84．______
you driving, don’t look back with only one hand on the 85．______
wheel. You’d better stop the car. 86．______