Volunteer tutor needed: biology for a motivated student in Sacramento

My younger brother, Wei, is 17 and in Form 3. Wei loves school but biology has been a struggle since the school was closed during the floods. The university entrance exam is in July. We can't afford a private tutor, and the school's free sessions are full. We're looking for a volunteer who could spend one or two hours a week, in person in Sacramento or online, for about sixteen weeks. Wei is polite, hardworking and eager. We have a quiet space and a laptop for online sessions. I'll always be at home for in-person sessions. If you're a teacher, student or professional who feels comfortable in biology, you could change the course of Wei's year. You're what makes this possible, and I'll never forget it.