巴氏分级法是临床较为常用的进行日常生活活动能力测定的有效方法，得分越低，独立性越好。康复效果越好，依赖性越小。
参考答案：错
–– When did they arrive?
–– They ______two hours ago .They ______ here for two hours .
A．arrived; have arrived
B．arrived; have been
C．got; have been
D．reached; have reached
奶牛的围产期是指母牛分娩前后（）天的时间。
