Saddle joints have concave and convex surfaces. name the two bones of the hand that articulate to form a saddle joint. a. the trapezium of the carpal bone and the thumb's metacarpal. b. the scaphoid of the index finger and the triquetrum of the middle finger. c. the trapezium of the ring finger and the capitate of the fourth finger. d. the scaphoid of the middle finger and lunate of the index finger.

When does a spring tide occur? question 9 options: they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur twice a year in the spring and fall. they occur on the date of the vernal equinox each year, no matter what stage the moon is in. this is why they are called spring tides. they occur when the sun, moon, and earth are at 45-degree angles from each other. this happens once every spring. they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur all year long.