Nothing, you can't cross a scaler with a vector.
A double crosser.
In a bucket.
A: A mosquito can fly, but a fly can't mosquito.
The mosquito.
Nothing! You can't cross scalars and vectors.
You can't cross a scalar and a vector.
Nothing, you can't cross a vector by a scalar. EDIT: changed multiply to cross.
Nothing, you can't cross a vector with a scaler.
You can't. A mosquito is a vector and the mountain climber is a scaler. Courtesy of my physics professor.