对诊断膀胱嗜铬细胞瘤有重要意义的是（）
A.头痛
B.心悸
C.腹痛
D.视物模糊
E.在排尿、膀胱充盈或按压膀胱时血压升高
参考答案：E
It is reported that the United States uses _______ energy as the whole of Europe. [ ]
A. as twice
B. twice much
C. as twice much
D. twice as much
下列有关纯合体的叙述中错误的是（）
A.由相同基因的雌雄配子受精发育而来
B.连续自交性状能稳定遗传
C.杂交后代一定是纯合体
D.不含等位基因
