诺贝尔奖得主杨振宁教授近日在中山大学演讲时说,上世纪初是物理学“遍地黄金”的年代,爱因斯坦26岁时一年能写出三篇震惊世界的文章,是因为“物理学几大原则问题正在等待破解”。爱因斯坦提出的理论及其作用是 ( )
Spring is coming.It's time________. A.to plant seeds B.plant seeds C.planting seeds
—Is there an apple on the plate?—Yes,________. A.there isn't B.there's C.there is
Boys are________football now. A.playingB.to play C.play
There________some water in the glass. A.areB.isC.am
根据图片选择答语。(20分) (1)What are they doing?________ (2)What are they doing?________ A.They are farming the land. B.They are looking at the flowers.