技术学习的重要特点（）
A、有目的的行为
B、没有风险
C、有层次性
D、有阶段性
E、很少涉及和外部组织的协作
参考答案：A, C, D, E
It’s the same in China --- many people, ________ some are not overweight at all, are always going on diets or taking weight-loss pills, ________ are often dangerous.
A．whose; which
B．of which; who
C．of whom; which
D．who; that
常见药物对胎儿的影响错误的是
A．反应停可导致“海豹”畸形B．抗癌药物在孕初3个月使用可引起各种胎儿畸形C．雌激素可导致男胎女性化D．孕期服用雄激素可生育男胎E．氯霉素可致灰婴综合征
