全陪带团外出旅游时,要热情为旅游者服务,但不应过分亲热,要努力维护旅游团的团结,但不介入他们的内部矛盾。
参考答案:对
如图为某化学反应的速率与时间的关系示意图。在t1时刻升高温度或增大压强,速率的变化都符合示意图的反应是:
A.2A(g) + B(g)2C(g) ΔH>0
B.2SO2(g)+ O2(g) 2SO3(g)ΔH<0
C.H2(g) + I2(g) 2HI(g)ΔH>0
D.4NH3(g)+ 5O2(g) 4NO(g) + 6H2O(g)ΔH<0
It's the second time you _______ late this week.[ ]
A. arrive
B. arrived
C. have arrived
D. had arrived