Why not ______ exercise more? [ ]
A. to try
B. try to
C. trying to
答案：B
常用的热轧带肋钢筋级别为Ⅱ级，牌号主要有（），
A.HRB300
B.HRB335
C.HRB400
D.HRB435
E.HRB500
张热常见的疾病是
A．伤寒
B．肺炎
C．支气管炎
D．败血症
E．布鲁菌病
