T•JK3-A型减速器制动轨磨耗极限高度为（）mm。
A.150
B.158
C.152
D.160
参考答案：B
As soon as they arrived in the big city ,they found it difficult to find somewhere cheap__________
A．to live
B．to live in
C．to live on
D．living
正常妊娠6~8周，其血液hCG每日增长速度应（）
A.≥100%
B.≥66%
C.≥55%
D.≥22%
E.≥120%
