直接影响DNA结构和功能的抗癌药是()。
A.环磷酰胺
B.巯嘌呤
C.甲氨蝶呤
D.氟尿嘧啶
E.阿糖胞苷
参考答案:A
给下列图片选择恰当的句子。
A. ( ) B. ( ) C. ( )
D. ( ) E. ( )
1. Don't turn left here.
2. China sent this present to the UN in 1974. It's a train.
3. The snake thinks the flute is another snake. So it copies the other snake.
4. Look at this postcard. There are lots of bicycles in China. People ride them to work.
5. I have got some chopsticks, but they are difficult.
薄壁不锈钢管是一种新型的室外管材。