31.______ should be made with great care.
问题描述:
31.______ should be made with great care.
A. So useful an experiment
B. So useful experiment
C. Such useful experiment
D. Such an useful experiment
答
with great care.意思是小心翼翼的
选择D 意思是他小心翼翼完成了 一次很有用的经验