甲型流感病毒（H1N1）是一种RNA病毒，如图是H1N1侵入人体细胞后发生免疫反应的某个阶段示意图，下列相关叙述正确的是（ ） A．因为有吞噬细胞参
Dear Mrs. Smith, I was a student of yours in Grade Six, and I hope you still remember me. I'm writing this letter becau
在中国封建社会时期，女子应具有“三从四德”，到清末和民国初年，女子应享有六种权利：（一）入学之权利。（二）交友之权利。（三）营业之权
For years we have been told that encouraging a child＇s self-respect in important to his or her success in life .But child expert are now learning that too much praise can lead to the opposite effect
在某高处A点，以v0的速度同时竖直向上与向下抛出a、b两球，不计空气阻力，重力加速度为g,则下列说法中正确的是 A．两球落地的时间差为2v0/g
兴奋在神经纤维上的传导是通过膜内外电位的变化产生（ ） A．电荷 B．局部电场 C
We haven’t settled the question of __________ it is necessary for him to study abroad. A. if B. where C. whether D. that
下列说法正确的是（设阿伏加德罗常数的数值为6.02×1023）( )。 A．在标准状况下，22.4 L苯所含分子数目为6.02×1023 B．1 mol／L K2SO4溶液所含K+数
