The growing speed of a plant is influenced by a number of factors，____are beyond our control.

Lady Gaga has put off her concerts because of thedifficulties ______ by the ongoing strikes.

I have no doubt in my mind______ they will be glad to see me.

Some equipment as well as a number of mapsand books toZhouqu since the mud-rock flow occurred.

We must work hard to ________ a good knowledge of English.[ ]