Certain treatments are usually started right awaya heart attack is suspected, even before the diagnosis is confirmed.which one is not correct for the blank?
A. once
B. if
C. so
D. when
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气缸直径是指柴油机气缸的()圆孔直径。
A.内
B.外
C.内、外平均
D.活塞
The three most common types of cancer treatment are surgery, radiotherapy and chemotherapy,aim at removing the cancer cells or destroying them in the body with medicines or other agents.
A. which
B. what
C. who
D. that
柴油机正常工作时,滑动轴承的轴颈与轴瓦之间应处于()状态。
A.液体摩擦
B.干摩擦
C.边界
D.半干摩擦
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