诗人左思在其《咏史》中沉郁悲歌:“世胄蹑高位,英俊沉下僚。地势使之然,由来非一朝。”造成这一社会状况的制度原因是
Frank and his friends had great fun _________volleyball on the beach yesterday.
play
playing
to play
Although it is raining _________, the policemen are still on duty in the street.
clearly
directly
heavily
Mr. Huang is an excellent English teacher who has over 20 years' teaching _________.
experience
information
knowledge
Uncle Liang has a great collection of _________watches.
enjoyable
valuable
comfortable
Eight members of a Chinese team arrived _________the top of Mount Qomolangma successfully.
in
at
to