单项选择题 Fill in the blank with the most appropriate choice. The experimental investigation __________ that the addition of these fibers reduces the thermal conductivity of the composite specimen and yield a lightweight.

单项选择题 After a slow start, the plan soon took ______and was accepted by all.A.force boys to hide their emotions to be “real man”B.help to cultivate masculine aggressiveness in boys C.encourage boys to express their emotions more freelyD.naturally reinforce in boys that traditional image of a man

问答题 不同税率的产品组成套装销售，若能分别核算，可分别不同税率计税。（    ）对 错