为了避免吸入汽车尾气和（），不要带婴儿去街边玩耍或长期停留。
A、避免车祸
B、吸入铅尘
C、避免丢失
D、避免生病
参考答案：B
The archaeologists found gold coins and pottery in the lowest level of the site____ they reached three months ago．
A．what
B．for which
C．that
D．to which
两根平行的直导线同时通入相反方向的电流时，相互排斥
