比如，含75％氧化铀的某种沥青铀矿物质的放射性是铀氧化物放射性的4倍。

Thus, certain pitchblendes containing 75% of uranium oxide are about four times as radioactive as this oxide.

youdao

比如，含75％氧化铀的某种沥青铀矿物质的放射性是铀氧化物放射性的4倍。

Thus, certain pitchblendes containing 75% of uranium oxide are about four times as radioactive as this oxide.

youdao