【模拟试题】
1. The children_____ to swim last month and they can swim very well now.
A. are taught B. were taught C. have taught D. taught
2. —Look ! What a nice garden ! —Yes. It _____ every day.
A. has been cleaned B. is cleaned C. is being cleaned D. was cleaned
3. It is said that potato chips_____ by mistake a hundred years ago.
A. invent B. invented C. are invented D. were invented
