what are we_____to do atschool?--oh,we have many school rules.

what are we_____to do atschool?--oh,we have many school rules. l know Mr Brown;we_____to each other at an international conference.A.are introduced B.have been introduced C.were introduced D.had been introduced 1.----Why is the classroom so dirty?----Sorry,sir.It_____yesterday.We forgot to do it.A.don't clean B.didn't clean C.weren't cleaned D.wasn't clean2.We_____to go into the school unless we are in school uniforms.A.allow B.are allowed C.are not allowed 1.----Why is the classroom so dirty?----Sorry,sir.It_____yesterday.We forgot to do it.A.don't clean B.didn't clean C.weren't cleaned D.wasn't clean2.We_____to go into the school unless we are in school uniforms.A.allow B.are allowed C.are not allowed What beautifl clothes__!A.are they B.are their C.they are D.then are （ ）their hats? A.where is B.where are C.what is D.what are _____uunder the bed?A.What B.What are C.What is D.Which （ ）___super calculators computers are A.What B.What a C.What an D.How useful work they are doing!A.What B.what a C.How a D.howHis parents teachers.Aboth are B.are allc.all are D.are both what are what are what,are, what are what are What are what are what ---used as chief building materials today -----steel and concrete.c.are are d are is what ---used as chief building materials today -----steel and concrete.c.are are d are is