凝血过程中，起反馈加速（催化）的因子是（） A.钙离子 B.组织凝血活酶 C.因子Ⅹ

allow   health  busy   fault  different

小题1:This adds to the traffic and pollution, but it’s not her _____________.
小题2:It’s the _____________ season in China because of Spring Festival.
小题3: Ask him if he wants to write something about staying ______________.
小题4: In fact, even the simplest everyday activities can make a real ___________to the environment.
小题5: You are not _______________to touch the exhibits.