bromyrite

bromyrite

1. Bromyrite crystals have a diamond-like luster and are usually colorless, but they darken to brown when exposed to light.

溴银矿水晶石有着钻石般的色泽,通常为无色,但是当暴露在阳光下后它们会逐渐变成暗褐色.

2. Bromyrite crystals (have) a diamond-like luster and are usually (colorless),but they (dark) to brown when (exposed) to light.

答案C，改为darken，but这里是conj.，句中缺v.，所以把dark改为v.形式。