先天性睾丸发育不全患者体细胞中有一条额外的X染色体，影响睾丸发育。()
参考答案：对
The students had to finish their homework on time, _______? [ ]
A. didn't they
B. must they
C. did they
D. hadn't they
拉丁美洲的民族独立运动粉碎了西班牙、葡萄牙的殖民统治，创建了17个独立国家。这些国家独立后大多选择了[ ]
A、资产阶级君主立宪制
B、封建君主制
C、三权分立的联邦制
D、资产阶级共和制
