6433-(433-187)的简便算法是[ ]
A.6433+187-433
B.6433-433+187
答案:B
布氏杆菌可以引起
A.回归热
B.风湿热
C.登革热
D.波浪热
E.Q热
—Do you know where David is? I couldn’t find him anywhere.
—Well. He _________have gone far—his coat’s still here.
A.shouldn’t
B.mustn’t
C.can’t
D.wouldn’t