It’s necessary ______ us to keep our pets clean everyday.
A、ofB
暂无解析
Ithink____importanttolearnEnglishwell.
Sometimesabus____getsonthebustocheckthetickets.
GreatasNewtonwas,manyofhisideas____todayandarebeingmodifiedbytheworkofscientistsofourtime.
Thecaris_____expensive_____hecan’tbuyit.
Theforeigners_________there,butthey_________thefoodthereatfirst.
