Scientists photographed for the first time ever _____ wild gorillas used a stick to test the depth of a pool before getting into it, according to a recent study.
| A．which | B．what | C．that | D．when |
He failed in the exam, ____ proves that he wasn’t working hard enough.
| A．which | B．what | C．it | D．that |
During the week ____ he tried to collect materials for his article.
| A．following | B．followed | C．to follow | D．that followed |
____ was expected, he succeeded in the exam.
| A．It | B．Which | C．As | D．That |
He studied hard and later became a well-known writer, ____ his father expected.
| A．that was what | B．what was that |
| C．and which was | D．which was what |
We should read such books ____ will make us better and wiser.
| A．when | B．as | C．whose | D．what |