通过基因工程改造后的菌株被称为（）.
A.“蛋白菌”
B.“工程菌”
C.“酶菌”
D.“细胞菌”
参考答案：B
从十月革命胜利到30年代中期，苏俄（苏联）曾经实行过哪些重要的经济政策？（4分）分别说明这些政策产生的影响。（12分）
He had studied hard, he would have been able to pass the exam.()
A. He had studied harder
B. If only he studied more
C. Had he studied harder
D. When he studied more
