601. I appreciate John's helping in time．
602. I bought it the day it was released.
603. I doubted whether the story is true．
604. I learnt that I had passed the test．
605. I will seek from my doctor's advice．
606. Ice cream is popular among children．
607. I'd like to get this film developed．
608. In a word，I am tired of everything．
609. Let us do it by ourselves，will you?
610. May I know the quantity you require?
611. Nobody has ever solved this problem．
612. Our school covers 100 square meters．
613. People enjoyed the stamps very much．
614. The editor over looked a print error．
615. The sudden barking frightened Clara．
616. The teams are coming onto the field．
617. There is a mark of ink on his shirt．
618. There isn't any water in the bottle．
619. This joke has gone a little too far．
620. We arrived in London this afternoon。