“A good book for children should simply be a good book in its own right,” says Mollie Hunter. Born and brought up near Edinburgh, Mollie has devoted her talents to writing primarily for young peop
As shown in the diagram(如图),the triangle PQR has PR=14cm and PQ=10cm. The side RQ produced meets the perpendicular PS at S, so that QS=5cm. The perimeter(周长) of triangle PQR is _____cm.
The two friends _____ on the Internet for three hours, and they would go on till the next morning. A. had been chatting B. had chatted C. were chatting D. has been chattin