汽车总的重量不超过5吨，若用g表示汽车重量，则g______5．
g≤5．
It is good news to us that we are invited to such a great concert, _____?
[ ]
A. is it
B. isn't it
C. are we
D. aren't we
伤寒第3～4周时阳性率最高的是
A．骨髓培养B．血培养C．尿培养D．粪便培养E．肥达反应
