A friendship may be ______, casual, situational or deep and lasting.
A. identical
B. original
C. superficial
D. critical
上期日习题及答案:
Cars moved very slowly in the 1920s, but they ______move more quickly than in 1910.
A. were to can B. did
C. will D. can
标准答案是：B.
本题分析：
did用在动词前，起强调作用。