基因芯片的实质是一种()
A.高密度的单克隆抗体阵列
B.高密度的多肽阵列
C.高密度的核酸阵列
D.高密度的寡核苷酸阵列
E.高密度的蛋白阵列
参考答案:C
To keep healthy, Mr. Smith_______ cycling as a regular form of exercise after he retired.
A.took up
B.put up
C.gave up
D.made up
如图所示一截面图形,则对y轴的形心主惯性矩为()。
A.1.01×106mm4
B.1.01×107mm4
C.1.61×106mm4
D.1.61×107mm4