Four days before the national college entrance exam, students from a south China school posed for photos Thursday in knee-deep flood waters on their campus.

The No. 2 High School in Du'an County of Hechi, a city in Guangxi Zhuang Autonomous Region, was one of the worst-affected by rainstorms that began pounding Guangxi Monday.

Huang Shizhao, a third-year student, said he woke up Tuesday morning to find water pouring into his dorm. "The river close to our school had burst its banks and flooded the campus."

The floods stopped some classes, but Huang and 1,000 schoolmates stayed to make last-minute preparations for the test of their lives, the national college entrance exam that will begin Monday.

The test result will decide whether they will go on to college or revise for another year, or join the migrant millions to take low-skilled jobs away from their homes.

They trekked through the knee-deep water several times a day between classrooms, dorms and their teachers' offices. A red signboard stood on campus, reading "The real test: 4 days to go".

Some students sat high up the bunk beds in their dorms to read in comfort. Their sandals were all put in buckets to avoid being washed away.

"It's quite exciting to see so much water," said Huang Chunhua, a girl. "I hope we all do well in the test."

By midday Thursday, the flood waters had not subsided on campus.

"We posted teachers to keep watch at dorms, classroom buildings and main passageways on campus to ensure students' safety," said vice principal Yu Shengzhong.

The school also cordoned off retaining walls, fearing they might collapse, said Yu.

He said the flood water would drain in two days.

The rainstorms were a real challenge for Guangxi. In Du'an county alone, the rain stopped classes for more than 20,000 students at 84 primary and secondary schools, the local flood control and drought relief office said in a statement.

In Laibin City, 65 schools were flooded and halted classes. At Laibin Experimental High School, where more than 1,000 students were stranded for hours before they were evacuated on small boats Wednesday, flood water was at least a meter deep Thursday.

The school principal Shi Fang said he could not tell when classes would resume. "The computer rooms, library, restaurant and science lab were all submerged," he said. "When the torrents poured into the classroom building, we could only evacuate the students, so most of the facilities were washed away."

Laibin City received a record 439 mm of rain Monday and Tuesday. At least 2,400 homes were destroyed.

Across Guangxi, the rainstorms had battered 27 counties and almost 80,000 people had been evacuated as of Wednesday night, the local government said.

Thirty-eight people were confirmed dead in landslides triggered by the rain, including 23 in Rongxian County, 12 in Cenxi and one each in Tengxian, Donglan and Fangchenggang.

At least 2,800 people were evacuated after their homes were destroyed by landslides.