When do you have _____? [ ]
A. a science
B. science
C. the science
D. science class
答案:B
以下是构成蛋白质的氨基酸的是[ ]
A.H2N—CH2—COOH
B.H2N—CH2—CH2OH
C.H2N—CH—CH2—COOH
D.
“Man is the measure(尺度)of all things.”这一主张的提出者应该是
A.Thales
B.Protagoras
C.Socrates
D.Aristotle