问题

It was very difficult to rescue the drowning boy in the sea. One moment the rescue workers ____him butthe next moment they _____.[ ]
A: caught sight of; lost
B: caught the sight of; lost his sight
C: caught sight of; lost sight of him
D: caught the sight of; lost their sight of him
B: caught the sight of; lost his sight
C: caught sight of; lost sight of him
D: caught the sight of; lost their sight of him
正确答案是: