问题
多项选择题
脉冲式安全门测试通过速度时,选择到DS位置,不可在()档范围内选择。
A.0—9
B.0—90
C.0—99
D.0—900
答案
参考答案:B, C, D
脉冲式安全门测试通过速度时,选择到DS位置,不可在()档范围内选择。
A.0—9
B.0—90
C.0—99
D.0—900
参考答案:B, C, D
An Event of Imagination
Reasons | Results |
One piece hits the South Atlantic at 200 times faster than the speed of sound. | The sea (46) and a huge hole is made in the seabed. A tsunami(海啸) hits southern Africa, (47) cities on the African coast, and (48) millions of people. |
A (49) (50) happens when the four-kilo- meter-wide piece of comet enters the Earth’s (51) | The sun is (52) . by clouds of dust and the temperature falls to almost zero, (53) crops. Wars break out for food and only 10 million people remain. The human beings are (54) the danger of (55) out. |