社会保障机制含有：（）。
A、风险分散机制；
B、风险共担机制；
C、社会稳定机制；
D、社会互助机制；
E、风险集中机制。
参考答案：A, B, C, D
肠套叠的典型X线征象是
A．出血速度快，呕血或便血B．出血速度较慢，便血为主C．出血伴腹痛，高烧D．少量便鲜血E．腹痛、发热、黄疸
Unsatisfied ________ with the payment, he took the job just to get some work experience.[ ]
A. though was he
B. though he was
C. he was though
D. was he though
tisfied ________ with the payment, he took the job just to get some work experience.[ ]