营养状况不能用尿负荷试验进行评价的是()
A.钙化醇
B.硫胺素
C.核黄素
D.抗坏血酸
E.烟酸
参考答案:A
解析:钙化醇为脂溶性维生素,其营养状况不能用尿负荷试验进行评价。
— Jenny took the 8:00 bus to Guangzhou this morning.
— Really? He _____ the 9:00 train. It's much more comfortable and safer to travel by train. [ ]
A. could have taken
B. should take
C. must have taken
D. can take
使用以MOV(氧化锌压敏电阻)为主要元件的箝压型SPD,因MOV老化或寿命终止,可能会造成相线对地短路,因此SPD应有()功能,并应在SPD的前端串接过流保护装置()。