Yes, a-Ying is smart and great at everything. 

(Brenda does not actually say anything to a-Ning because he is reading a book and she has (her own notion of) good manners.)

Radio maintenance is not quite as fun as biology but it is very fun.

About halfway through the radio project he gets distracted by the spirographs, and then he gets distracted by trying to understand exactly what the slime molds are up to.

She has a complete explanation of the spirographs, and an incomplete but extensive explanation of the slime mold across several levels of abstraction from mathematics to physiology, and absolutely no sense of time, so if neither of them remembers that they're supposed to be building a railgun they're supposed to be building a trebuchet and were planning on building a railgun they're just going to stay sidetracked until her mother yells that it's dinnertime.

"...Shit. I should probably be getting-- somewhere other than home. A-Ning, what's for dinner?"

"Pizza but my mom's still mad about you bleaching the couch."

"Your mom doesn't care about science. This is why there's widespread scientific ignorance, you know. People not supporting teenagers in their experimentation. Valuing their couches over the advancement of human knowledge. Also, I think it looks better that way. It's unique. You're not going to have any other couch with that pattern of bleach stains. You could probably sell it as a piece of abstract art."

Brenda has tripped the circuit breaker, clogged the sink, and neglected to declare the pet praying mantis too many times to throw stones. "I can ask if you can have dinner with us if you want, but warning that Mom will complain about not having been told in time to make more food and Dad will complain about me having boys in my room."

"We could give them something to complain about if they're going to complain anyway."

"I'd rather not give them any more things to complain about," Brenda says, the innuendo whooshing so far over her head it doesn't even ruffle her hair.

"Ouch. Crushingly rejected."

It's not surprising that he's the sort of person who would trip the circuit breaker or whatever as a prank but she does actually like her parents when they're not being annoying.

"Sorry? I don't know why you'd want to, surely you get plenty of opportunities to mess around elsewhere." 

"But I don't want to mess around elsewhere! I want to mess around with you!"

"I'm glad. Just--let's get downstairs. On my way, mom!" She goes downstairs first to explain things to her parents.

"a-Ning, did you see how badly she rejected me. I'm crushed. I'm destroyed. I have never been so thoroughly blown out by a girl in my life."

Pat pat. "Maybe she's a lesbian."

"Oh! That's true. Do you think we could set her up on a date with your sister? She's cool and Wen Qing is cool and so together they'd be the most cool."

Brenda comes back upstairs and says, "Okay, come on down, they made enough for leftovers and I said I would cook tomorrow instead so it's fine. If you like spaghetti and meatballs and broccoli."

"Bet they're not spicy enough."

"A-Ning, you should go home for dinner." This opinion is accompanied by Wei Wuxian pouncing on him and giving him a full-body hug.

"They are basically zero spicy, sorry. Uh, do you want to come down and eat or not?"

"I'm going to come down to eat and I'm also going to complain!"

A-Ning nervously waves goodbye to both of them and leaves.

"Goodbye. Um it was nice meeting . . . " aaand he's already gone, never mind.

She leads Wei Wuxian down to the kitchen and says "Mom, Dad, this is Wei Wuxian, my friend from school."

"Did you have him in your room with you?" 

"Dad, we were working on a science project!" 

Mr. Banner responds with a suspicious glare; Mrs. Banner looks, if anything, disappointed. Brenda determinedly goes and starts filling everyone's water glasses from the sink, pointing out which chair is the guest chair on the way.