(____)1. A. school B. plane C. ship
(____)2. A. take B. pick C. train
(____)3. A. skate B. book C. jump
(____)4. A. near B. why C. who
(____)5. A. clothes B. prince C .fairy
将一个凸透镜正对太阳,在距凸透镜20cm处得到一个最小、最亮的光斑.将一个物体放在此透镜前30cm处,则可在凸透镜的另一侧得到一个( )
—Yes, I just bought _______ the other day.
地沟油中含有一种强烈致癌物黄曲霉素B2(C17H14O6),长期食用会引起消化道癌变。下列关于黄曲霉素B2的说法正确的是( )