As we know, too much ________ to Xrays

搜题请搜索小程序“爱下问搜题”

问题选择题

As we know, too much ________ to Xrays can cause skin burns, cancer or other damage to the body.

A．contact

B．appeal

C．exposure

D．contribution

答案

答案：C

C　[exposure to sth harmful“面临(有害物质)，遭受”。]

填空题

质量相等的木块和冰块分别放在酒精和水中，静止时都漂浮在液面上，它们受到的浮力分别为F_水和F_酒，排开液体的体积分别是V_水和V_酒，则 F_水______F_酒，V_水______V_酒．

单项选择题

无符号二进制整数01011010转换成十进制整数是

A．80

B．82

C．90

D．92