如图3-311所示梁的弯矩图形为下列何图()
A.A
B.B
C.C
D.D
参考答案:A
解析:
弯矩M使杆件上端受拉,左端弯矩为零。
—We should adopt ________methods to deal with some incidents. You know,anything could occur in that situation.
—I got it. Thank you for reminding me.
A.flexible
B.typical
C.positive
D.concrete
支气管炎患者,发热咳嗽,用头孢曲松2周无效,改用红霉素见效。从患者痰中分离一株病原体细胞培养、鸡胚培养和动物接种均生长,它可能是()
A.细菌
B.真菌
C.支原体
D.立克次体
E.衣原体