【单选题】Those boys are _____ .
【单选题】________two boys are Mr. Green's sons. A. This B. These C. That D. those
【单选题】The reason why the toys most boys play with are different from those that girls play with is that ______.
A.
their social roles are rigidly determined
B.
most boys would like to follow their fathers' professions
C.
boys like to play with their fathers while girls with their mothers
D.
they like challenging activities
【单选题】Look! Those boys ________ football.
【单选题】不 需要考虑低位来的进位的加法器是( )
【单选题】各种微生物的生长繁殖与其周围环境的酸碱度有密切关系,大多数霉菌和酵母菌适宜在PH值为( )的环境中生长。
【简答题】微生物生长的基本条件有哪些 ? 2. 根据最适生长温度的不同,微生物分为哪几类? 3. 微生物适宜在怎样的渗透压下生长 ? 生理盐水的浓度是多少 ? 4. 根据微生物生长的最适 pH 值,微生物分为哪几类? 5. 细菌、酵母菌、霉菌、放线菌的最适生长的 pH 值是多少? 6. 根据微生物生长对氧气的需要可分为哪几种类型?