某小组进行“培养液中酵母菌种群数量的动态变化”的实验,在下列实验材料用具中,属于本实验需要的是[ ]
A.琼脂块
B.双缩脲试剂
C.放大镜
D.显微镜
答案:D
A lot of food as well as some tents _________to Yushu since the earthquake occurred.
A.has been transported
B.have been transported
C.is being transported
D.are transported
()是从饲料总能中减去粪能后的能值,亦称“表观消化能”。