12.It took us over an hour_______along the street.
A.walk
B.to walk
C.walking
D.walked
答案:B
一 I like a pen which _____ well.
一 Will this one _____? [ ]
A. writes; work
B. is written; do
C. writes; do
D. is written; work
我国奶牛业发展历程的几个阶段及特点?